Sweet Potatoes – Grow. Cook. Eat.

September 23, 2011

Free Samples (Recipe: Sweet Potato Burgers)

Last weekend, I was in DC for a book-signing with my dear friend, and co-author, Brett. When I do these types of events, I find the easiest way to lure people to my table – to talk with them about farmers’ markets (or promote the cookbook), is to offer a free sample. And since I had the opportunity to get produce from Brett's farm, it only seemed logical to use what he had.

But the options from the farm were limited. Even’ Star is still reeling from the effects of Hurricane Irene and Tropical Storm Lee. They've long since left the newsfeed, but that doesn’t mean that the tomatoes suddenly began producing again, or the melons became sweet again.

So we were limited to sweet potatoes, red peppers and eggplants. The weather is quickly turning to autumn, and even though there are still remnants of summer at many of the farmers’ markets, we decided to stick with a more fall-like recipe: sweet potato burgers.

If you’re a die-hard carnivore like me, it’s hard to get excited about veggie burgers. And to be honest, it’s not something i would make if left to my own devices. But these straightforward burgers are satisfying and delicious. The sweet potatoes have enough starch in them to maintain their shape. With the addition of black beans, they have plenty of protein. And fresh herbs brighten up the flavors.

We served these with our homemade ketchup and sour cream mixed with wild mushrooms.

Vegetarian Sweet Potato Burgers

From The Farmer’s Kitchen: The Ultimate Guide to Enjoying your CSA & Farmers’ Market Foods

2 tablespoons olive or canola oil
½ cup minced onions
3 cloves garlic, peeled and chopped
2 cups cooked black beans, slightly mashed
¼ cup fresh oregano and/or basil
1 teaspoon salt
¼ teaspoon cayenne
2 cups cooked sweet potatoes, mashed (preferably a mix of different varieties)
salt and pepper to taste
Garnish: sour cream, cilantro and/or cheese.

In a large skillet over medium-high heat, add 1 tablespoon of the oil. Sauté the onions and garlic until just cooked. Immediately remove from heat.
Add the beans and oregano to the onions and garlic.
Sprinkle cayenne and salt on top of the mashed sweet potatoes. This helps to better disperse the seasoning.
Mix all ingredients together and chill for at least 45 minutes. Season to taste with salt and pepper.
Once chilled, form patties approximately 1 ½-inch thick and 4-inches in diameter.
Heat a large skillet over high heat, add remaining oil. Fry patties until golden brown and crispy on both sides. Flip gently, as these burgers don’t hold together as well as meat patties do.
Serve with sour cream mixed with fresh cilantro, or any condiment that you would normally serve with a beef burger. Best to serve with toasted crusty bread such as baguette or Kaiser roll.

August 3, 2011

Down on the Farm

I'll be heading down to the farm this week for my annual trip to can tomatoes.

In the last two years, I've really upped my production — last year I canned 72 jars! Normally, I hoard my stash all winter long, but this year, I still have two dozen jars left of stewed tomatoes. I've become a bit more carefree in my use.

The other night I made a quick ketchup/BBQ sauce; and served it with Seared Foie Gras…

BBQ Foie Gras with Sweet Potato Biscuit and Grilled Onions

1 jar tomatoes
1 small onion diced
pinch cinnamon
pinch allspice
pinch chile flakes
1/4 cup brown sugar
1/4 cup cider vinegar
3 fresh onions
olive oil
6 – 1 oz. slices of fresh foie gras
sweet potato biscuits
salt and pepper to taste

1. In a small sauce pan, combine the first 7 ingredients. Simmer over medium heat for 1 hour. Puree. Season to taste with salt and pepper and set aside.

2. Prepare a charcoal grill. Cut onions in half, lengthwise, through the root, so that the root can hold each half together. Toss onions with olive oil and season with salt and pepper. Cook on the grill until roasted and tender, about 20 minutes.

3. Cut biscuits in half.

4. Heat a large skillet over a high flame. Season foie gras with salt and pepper. Press the foie into the hot skillet and let sear for 2 minutes until dark golden brown. Flip over for 10 seconds and remove from pan.

5. Place a slice of foie on the bottom half of each biscuit. Put the top on. Serve with grilled onion and pureed tomatoes.

Sweet Potato Biscuits

3/4 cup milk
1 tsp. yeast
2 cups A/P flour
2 tbs. baking powder
1 tsp. salt
5 tbs. butter
1/2 cup cooked sweet potatoes.

1. Dissolve yeast in milk and set aside.

2. Combine flour, salt, sugar and baking powder in a bowl. Sift or whisk to break up any clumbs and to well combine.

3. Cut butter into chunks and then work the butter into the flour mixture until the butter is mostly combined but still chunky.

4. With a few swift strokes combine the milk and sweet potatoes into the flour mixture so it forms into a ball.

5. Turn dough out onto a floured surface. Roll out to 1 inch thick. Cut into biscuits and lay on a cookie sheet. Let rest for 30 minutes or more.

6. Preheat oven to 425.

7. Bake biscuits for 10 – 15 minutes or until golden brown on top.

July 6, 2011

Grilled Sweet Potato Salad

In the summertime, grilling seems to be the favored cooking technique for so many reasons – we can cook without heating up the house, there are no pots and pans to scrub, and we get to be outside in the garden.

Last year, on the Fourth of July, in keeping with the holiday tradition, I grilled hamburgers… it went against my general style of entertaining in that I usually cooking everything ahead of time. But I thought, “How hard can burgers be? Even if for 12 people.” Actually, it was a nightmare (okay, maybe that’s an exaggeration, but it wasn’t great). Instead of drinking G&T’s and chatting with my guests in the garden, I was contending with an overcrowded grill that was flaring up from all the fat drippings, shuffling around patties and buns.

This year, I still grilled but went back to my usual mode – cooking everything ahead of time. My “barbecue” still had the summertime mark of grilling, without the stress created by live fire. I twisted around an old favorite into Grilled Flank Steak with Grilled Sweet Potato Salad and Cilantro Mojo. The flank steak was seasoned with fresh oregano, lime juice, salt and pepper before grilling.

Sweet Potato Salad
Adapted from the Weber Cookbook courtesey of Dan Kirsch.

3 large sweet potatoes (about 2 pounds)
2 – 3 stalks celery, diced
2 red bell peppers
3 scallions, cut into rings
¼ cup cilantro sprigs, chopped

Dressing
6 tbs. olive oil
3 tbs. lime juice
1 clove garlic, or 1 garlic scape
1 small jalapeno, diced (remove seeds first for a more mild dressing)
1 tsp. salt
½ tsp. ground cumin

1. Combine all ingredients for dressing.
2. Peel sweet potatoes and cut lengthwise into ½ inch thick slices
3. Toss sweet potato slices with about 3 tablespoons of dressing.
4. Prepare a charcoal grill on one side of the grill.
5. When it’s hot, blacken the skin of the red peppers on all sides and then put in a stainless steel bowl, covered with plastic.
6. Grill the sweet potato slices on the hot side of the grill until nicely marked on both sides. If there’s dressing leftover in the bowl, save to add to the salad at the end. Move the slices to the cool side of the grill. Cover the grill, leaving the vents open, to “roast” the sweet potato slices until tender, about 15 minutes.
7. Meanwhile, peel away the blackened skin of the peppers, and scrape out the seeds. Dice the peppers and toss them, along with the scallions and celery in the dressing.
8. When sweet potatoes are tender, remove from grill and dice. Add to the other veggies and toss with cilantro and extra dressing.
9. Adjust seasoning with salt and pepper.

March 4, 2011

Freezing Sweet Potatoes

This sweet potato could feed a family of four. For a week. And despite its appearance, no steroids or growth hormones were used. It came from my friend Brett’s farm – Even’ Star – in Southern Maryland; who, by the way, was just featured yesterday in an article in the Washington Post.

I was cooking dinner a few weeks ago for me and a friend. After cubing just a quarter of it, I knew I there would be way more potatoes than we could eat. And with a fear of the remainder languishing in the ‘frigde until I got around to cooking it, I decided to experiment with freezing.

Sweet potatoes sometimes oxidize. Not as much as apples or russet potatoes, but they get enough black streaking that I thought freezing them in the raw form would not be a good idea. Instead, I par-boiled the cubes in salted water for 2 minutes, just enough to destroy whatever oxidizing components there might be.

I laid the par cooked cubes on a cookie sheet lined with parchment paper and popped the whole thing in the freezer.

A few weeks later, I used the frozen sweets to make sweet potato raviolis. Everyone loved them!

Because I pureed the sweets, there were no issues with texture. I still want to experiment – and try roasting the pre-frozen cubes to see if they develop a crust or if they just fall apart.

As Brett says, “Very large sweet potatoes are unjustly scorned by novices, but old-time Southern cooks treasure the mammoths for ease of use. They also know that a slowly grown but big sweet potato is more flavorful than a typical conventionally grown, smaller sweet potato whose growth was rushed and babied with agricultural chemicals.”

So don’t be shy about the very large sweet potatoes. Know that whatever you can’t use on the first day can be frozen for a later preparation.

July 7, 2008

Adventures in Sweet Potatoes

Four Burgers opened up just a month ago in Central Square with the mission of serving high quality, simply prepared burgers and fries. In this modern era of eco-friendly dining, they do the right thing by composting, recycling, and serving ingredients with known provenance. The net result, for the most part, is fabulous: Juicy, meaty burgers with flavorful toppings and fries that taste like potatoes.

There’s been a small hiccup in the business—and that has been the sweet potato fries. While most would agree that anything fried and salted is better, these fries suffer in that they never get really crispy. Short of coating them with a non-organic/unnatural substance (as many lesser burger joints do), the options are somewhat limited.

The composition of the sweet potatoes creates a layered challenge with sugar, starch and water issues at play. Food science research leaves a gaping hole in this domain.

For regular potatoes, culinary experiments have yielded the best technique… first soaking the potatoes in water to rinse some of the excess starch, cooking the potatoes a first time in 325F oil and then a second cooking in 375F oil to crisp them. Intermediate refrigeration between frying further alters the starches which better enables a crispy fry. Researchers have discovered that Idaho potatoes are the best variety, and farmers have refined the genetics to consistently produce a fail-safe potato.

What works for regular fried potatoes does not translate to sweet potatoes because of the starch, sugar and water content.

And while there are a few sweet potato varieties out there (White Hamon) that are better suited, they are not mass marketed, leaving the small restaurateur to experiment with the readily available varieties.

The starch issue is a complicated one… And after researching in Harold McGee’s On Food and Cooking, I discover this is more complicated than I can address with chain starches and branch starches and the chemical reactions of both. The water and sugar contents pose a more straight-forward challenge. As we know, moisture is the enemy of crispy [[Think about meringues on a humid day or fried eggplant]].

In order to get “watery” foods crispy, we must first batter them to prevent the moisture from seeping out and soggying the crust. Sweet potatoes get crispy in tempura batter because they are sufficiently coated.

Alternatively, in the case of regular potatoes, the minimal water evaporates before the fry crisps up – creating a fry with long-lasting crispiness.

This is when the challenge of the sugar content kicks in: Sugar begins to caramelize about at 334F and starts turning bitter at 363F. This narrow window limits the opportunity for the sweet potato fry to rid itself of excess moisture and get crispy.

Armed with this (somewhat limited) knowledge base, Michael B. (owner of Four Burgers) and I got to work.

Our baseline was a sweet potato fry that was cooked in 350F oil until golden brown and soft in the middle. The fry was mildly crispy straight out of the oil, but quickly turned limp.

The first wave of experiments involved coating the raw fries with a type of starch that would help absorb moisture and increase the starches that would crispy up the fries. We tried corn, wheat and potato starches. And with a nod to the tempura batter, we also made a mix of corn and wheat flours. The best yield was the corn starch. Straight out of the fryer, the potato was crispier than the original, but soon met a similar fate of limpness – though the crisp to limp time gap was greater.

Other starches provided minimal improvement. The biggest complaint was that the floury coating took away from the flavor and “Mouth feel” of the potatoes.

The second round of experiments involved drying the potato first before frying. First, we “par-” fried the potatoes the way regular fries are. This seemed to produce a crispy fry but we soon realized that this extra step was minimal better than the baseline, and not worth the effort.

Par-Baking the potatoes yielded the best result. The potatoes dried out with a gentle heat. Unlike the fryer, the drying process did not brown (i.e. caramelize the sugars in) the potatoes. By the time we put them in the fryer, they crisped up quickly and stayed crispy.

Special thanks to Michael B. and his staff for allowing me to play in their kitchen! Stop by, have a burger and fries and let me know what you think!