Black Bean Burgers

Heat the oven to 425°F. Rinse and peel the sweet potatoes and trim away any dark spots. Halve them lengthwise and cut each half into 1/4-inch sticks. Drain and rinse the beans.

Line a large baking sheet with parchment paper and coat with 1 tablespoon oil. Toss the fries with the cornstarch in a plastic bag or bowl. Add 1 tablespoon oil and toss to coat again. Spread them out on the pan in a single layer. Roast until they brown and sizzle, 20 to 25 minutes; then turn and cook until the other side is golden, 5 to 10 minutes more.

Peel and halve the yellow onion, put it in a food processor, and pulse a few times to chop. Add the beans, oats, and chili powder with a sprinkle of salt and pepper. Run the machine in long pulses, stopping to scrape down the sides, until the mixture is combined but not puréed, no more than a minute total. Shape the bean mixture into 2 patties and put them on a plate. Split the English muffins and toast them (use the oven if you’d like). Rinse and dry the lettuce. Rinse the tomato and slice it crosswise. Peel the red onion and slice it thinly crosswise.

After turning the fries, put the remaining 1 tablespoon oil in a large skillet over medium heat. When it’s hot, add the bean patties. Cook, undisturbed, until they’re browned and crisp on the bottom (you’ll need to peek once or twice), 5 to 8 minutes. Add more oil if the pan looks dry, then carefully turn the patties with a spatula and cook until they feel firm and are browned on the other side, 3 to 5 minutes more.

Combine the cumin and half of the cayenne in a small bowl with a little salt and pepper. When the fries are ready, sprinkle them with the spice mixture and gently toss. Serve the burgers on the toasted muffins with the fixings you like and the fries on the side.