Roasted sweet potato fries

February 17, 2014 at 10:49 pm (Fall recipes, Quick weeknight recipe, Root vegetables, Starches, Uncategorized, unrated, Website / blog, Winter recipes)

I’ve decided to go on an elimination diet for a month, to see if it helps my allergies. I chose the foods to eliminate based on how allergenic they seem to be in general, as well as the results of a skin-prick test I had years ago. I decided to eliminate the three big allergens—soy, dairy, and gluten—as well as a number of other foods.

Today was my first day of what I call my “allergy-free” diet and I got home from work quite late and found very little in the fridge, since we were out of town all weekend and I didn’t get a chance to do my normal Saturday morning shopping. Normally I would throw together a pasta dish or a stir-fry with veggies and tofu, but today I had to be a little more creative. I found some sweet potatoes and a jar of giant white beans in the pantry, and so I improvised what turned out to be a quite tasty dinner of sweet potato fries and white beans with leeks and dill and parsley. (I had chopped herbs in the freezer.)


  • 2 sweet potatoes, washed but unpeeled (about 2 pounds total)
  • 2 Tbs. olive or coconut oil
  • scant 1/2 tsp. sea salt
  • 2-3 tsp. spices of your choice (I used curry powder, garlic powder, lots of black pepper, and aleppo pepper)


  1. Preheat the oven to 450 C / 230 F.
  2. Remove any gnarly parts of the sweet potatoes but otherwise leave the peels on. Cut each sweet potato lengthwise into planks about 1/2-inch thick. Stack the planks and cut them crosswise into batons about 2 or 2 1/2 inches long and 1/2-inch thick.
  3. Use 1 Tbs. of oil to oil the cookie sheet and then place the sweet potato batons onto the sheet. Sprinkle with salt and spices of your choice and drizzle on the remaining tablespoon of oil.  Carefully toss on the cookie sheet to distribute the oil and spices. (If you prefer you can do this in a bowl but I prefer to just be careful rather than to dirty another bowl.)
  4. Bake for 15 minutes and then flip the sweet potatoes and cook for another 5 to 10 minutes, or until starting to crisp up. You can eat them right away. If you prefer a crisper fry then turn the oven down to 200 F (about 100 C) and bake for another 10 to 20 minutes. The fries will lose moisture and shrink somewhat in volume, resulting in a slightly drier, more textured “fry.”

I looked at a number of recipes and the general recommendation seems to be 1.5 – 3 Tbs. oil for two pounds sweet potatoes. I found different suggestions for spices. One recipe called for black pepper, honey, and parsley. Another called for light brown sugar and black pepper. A third used coriander, fennel seed, oregano, and aleppo pepper. (I might try that one next time.)

The instructions for baking differed quite a bit among the recipes. One says to roast for 40-50 minutes at 450 F. Another says to roast at the same temperature for only 20 to 30 minutes. A third calls for only 20 minutes at the much lower temperature of 375! Why such different baking temps and times? Even more unusual: a Serious Eats recipe says to par-cook the sweet potatoes between 135 and 170 F to activate an enzyme that converts starch into a sugar (maltose), and let sit for an hour, and only then bake at 400 F for 50 minutes.

More about my elimination diet:

I first decided to eliminate the three big allergens (soy, dairy, and gluten). My allergy test to wheat was actually negative, but so many people say they feel better without gluten that I decided to try cutting it out, meaning no wheat, barley, or rye. I don’t mind giving up bread that much, as I don’t eat it that often, but I’m going to miss pasta!

I’ve also decided to eliminate (at least at the beginning) the other foods I had a positive allergy test to: corn, citrus, eggs, potato, pork, and chocolate.  (The pork is going to be an easy one!) You might wonder what foods I didn’t get a positive test result for, and the answer is wheat, yeast, tomato, tea, coffee, rice, buckwheat, and oats. It seems like a strange list of foods to test. They tested buckwheat and rice (which I’ve not heard of anyone being allergic to) but not peanut butter or tree nuts or strawberries?

I decided to eliminate peanut butter since I eat it quite frequently and it seems to be a common allergen, but to keep nuts in the diet. Because pseudo-grains are forbidden on many elimination diets, I’ve decided that at least at the beginning I’m going to try to avoid quinoa, amaranth, millet, and teff. Instead I’ll eat more starchy vegetables instead.  I will eat rice and buckwheat since my allergy test to them was negative and they’re rarely allergenic, and maybe oats too. Finally, I’m going to try to minimize added sugars and low-quality seed oils.

Together soy, dairy, gluten, eggs and peanuts comprise a large fraction of my protein intake, so I’m going to have to work to ensure that my diet doesn’t just contain carbs and fat.  Even though legumes are excluded on many elimination diets, I decided not to eliminate them (other than soy and peanuts), since without them I would really struggle to get enough protein.

Another set of foods that elimination diets often exclude are nightshades. But other than potatoes I’ve decided to leave them in since I tested negative to a tomato allergy and tomatoes and chilies go so well with beans, whether it’s black beans with salsa, greek-style white beans with tomato sauce and green peppers, or a spicy tomato-based dal.

So what does that leave me? What can I eat?

  • Green leafy vegetables and crucifers (escarole, kale, spinach, chard, arugula, bok choy, broccoli rabe, dandelion, lettuce, cabbage, broccoli, cauliflower, brussels sprouts, kohlrabi,…)
  • Starchy tubers other than potatoes (sweet potatoes, carrots, jerusalem artichokes, turnips, rutabagas, celery root, parsnips, winter squash, beets, daikon, radishes,…)
  • All non-starchy vegetables (celery, okra, fennel, green beans, peas, eggplant, zucchini, radicchio, endive, asparagus, artichokes, cucumber, bell pepper, tomato, snow peas, mung sprouts, garlic, onion, scallions, leeks, bamboo, seaweeds)
  • Fats (olives, avocado, coconut milk, shredded coconut, olive oil, coconut oil, flax oil, nuts except peanuts, seeds including flax seeds, hemp seeds, chia seeds)
  • Condiments like vinegar, mustard, pickles, nutritional yeast, …
  • Tea and coffee, carob powder and chicory powder,…
  • Spices and herbs
  • Rice and buckwheat
  • All fruit except citrus
  • All beans except soybeans

Depending on how things go, after a week or two I may start to add back in some foods such as eggs, pseudo-grains, ghee, fermented dairy from goat or sheep milk, or potatoes.

Going back to the question of protein: Let’s assume that I need about 50g of protein a day at minimum. If I consume 1.5 cups of legumes a day then that would yield around 23g of protein on average.

A serving of nuts or seeds provides about 5g of protein on average:

  • 2 Tbs. sunflower seed butter (32g) = 6g protein
  • 1 ounce almonds (28g) = 5.9g protein
  • 2/3 ounce pepitas (19g) = 5.7g protein
  • 1 ounce pistachios (28g) = 5.7g protein
  • 1 ounce cashews (28g) = 5.2g protein
  • 1/2 ounce hemp hearts (14g) = 4.7g protein
  • 1 ounce walnuts (28g) = 4.3g protein

If I eat two servings of nuts and seeds then my total would be up to 33g. Two serving of leafy greens or other higher-protein vegetable has about 5g of protein.

  • 1 cup broccoli raab (190g cooked) = 6.5g protein
  • 1 cup spinach (181g cooked) = 5.3g protein
  • 1/3 head cauliflower (275g cooked) = 5.1g protein
  • 10 brussels sprouts (200g cooked) = 5g protein
  • 2 cups kale (260g cooked) = 4.9g protein
  • cooked crimini mushrooms (6.5 ounces / 184g raw) = 4.6g protein
  • 1 large artichoke (152g cooked) = 4.4g protein
  • 1 medium stalk of broccoli (180g cooked) = 4.3g protein
  • 12 spears asparagus (180g cooked) = 4.2g protein
  • 2 cups sliced zucchini (360g cooked) = 4.1g protein
  • 4 oz. mesclun salad greens = 2.2g protein

So now the remaining foods I eat in the day need to make up the last 12g of protein. If I eat two servings of fruit each day that will add up to only about 1.5-3g of protein.

  • 150g raspberries = 1.8g protein
  • 148g kiwi = 1.7g protein
  • 150g sour cherries = 1.4g protein
  • 1/2 mango (168g) = 1.4g protein
  • 1 medium banana (118g) = 1.3g protein
  • 150g blueberries = 1.1g protein
  • 1 small apple or pear (150g) = 0.4 – 0.5g protein

I’m still about 10g short! How about starches? They seem to contribute about 3g per serving on average:

  • 3/4 cup cooked buckwheat groats (126g) = 4.3g protein
  • 1.25 cups mashed rutabaga (300g cooked) = 3.9g protein
  • 4 medium beets (200g) = 3.4g protein
  • 1 cup sliced jerusalem artichoke (150g raw) = 3g protein
  • 1.25 cups mashed celeriac (300g cooked) = 2.9g protein
  • 1.5 cups butternut squash (307g cooked) = 2.8g protein
  • 2/3 cup baked sweet potato (134g) = 2.7g protein
  • 2.25 cups cooked sliced carrots (347g) = 2.6g protein
  • 1 parsnip (171g cooked) = 2.3g protein
  • 1/2 cup medium-grain white rice (93g cooked) = 2.2g protein

So even with a serving of starch I’m still about 7g short. How can I fill in the gap? Probably more non-starchy vegetables, as so far I’ve only assumed two servings. For example, 3 servings (12 oz.) of a typical Asian stir-fry mix of vegetables has about 7g of protein.  But that seems like quite a bit of food to reach 50g of protein a day:

  • 1.5 cups of beans (about 350 calories)
  • 2 servings of nuts/seeds (about 300 calories)
  • 2 servings of fruit (about 175 calories)
  • 1 serving starchy vegetables, rice, or buckwheat (about 120 calories)
  • 3 servings other non-starchy vegetables (about 150 calories)
  • 2 servings leafy-greens, crucifers, or other high-protein vegetable (about 50 calories)

But adding it up it’s only about 1150 calories! Even adding in two tablespoons of olive oil (or other fats) there’s still plenty of room for larger portions of beans or starchy vegetables, or for some dried fruit for dessert.

1 Comment

  1. Tallulah Hoberman said,

    The Mediterranean diet that has been recommended to me several times includes three tablespoons of olive oil a day. That would help add calories.

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