avocado, tomato, thinly sliced red onion, sprouts (I used sunflower sprouts)
Make the burgers:
Place the grated zucchini in a large colander and toss with 2 teaspoons of salt. Let the zucchini drain for 15 minutes, then squeeze out as much moisture as you can with your hands (or roll it up in a clean kitchen towel and wring it out). Discard the zucchini water.
Place the coriander and cumin seeds in a small, dry skillet set over a medium-low flame and toast until fragrant, shuffling the pan frequently, 2-3 minutes. Let cool completely, then grind finely in a spice grinder or mortar and pestle.
Heat the oil in a wide skillet set over a medium flame until it shimmers, then add the onion, garlic, smoked paprika and the ground coriander and cumin. Cook, stirring frequently, until the onion is caramelized and tender.
In a large bowl, combine the cooked onion, chickpeas, drained zucchini, parsley and lemon zest. Use a potato masher to mash the mixture, leaving the chickpeas fairly chunky. Blend in the egg, chickpea flour, and ½ teaspoon salt. Gently stir in the feta, leaving it in chunks. The burger mixture can be prepared up to 2 days ahead and refrigerated airtight until ready to cook.
Make the yogurt sauce:
Mash the garlic and salt together in a mortar and pestle (or with a fork in a wooden bow until smooth. Work in the yogurt, then stir in the mint. (Can be made up to 1 day ahead.)
Cook the burgers:
Shape the burger mixture into 6 large patties, roughly 4" wide and 1" tall. Heat 1/8" of sunflower oil in a wide skillet set over a medium flame until it shimmers. Carefully add 3 of the burgers and cook on the first side until deeply browned, 3-4 minutes, reducing the heat if the burger is cooking too quickly. Flip and cook on the second sides until browned and the burgers are cooked through, 3-4 more minutes. The burgers are fairly dense, so decrease the heat to low if necessary to gently heat them all the way through. Drain on paper towels, and repeat with the remaining burgers. (Extra burgers can be refrigerated airtight for up to 3 days or frozen for up to a month or two; re-fry to heat through before serving.)
Eat the burgers!:
Spread the buns on each side with a tablespoon or two of yogurt sauce, then top with the burger patties, sliced avocado, tomato, onion, and sprouts. Devour immediately.
These burgers are vegetarian, gluten-free and grain-free, and would be equally delectable made into smaller cakes, fried in a little extra oil, and served atop a green salad.Don't skip the yogurt sauce as it adds needed moisture to the sturdy patties.Do be sure to squeeze the bejeezus out of the zucchini so you don't end up with soggy burgers.The burger mix can be made up to a day or two ahead and fried to order. Or cook up the burgers and store them airtight in the fridge or freezer. Cooked burger patties travel well and can be thrown on a grill to re-heat.I made these with home-cooked chickpeas; if using canned, you may need to add less chickpea flour to account for drier beans. If starting with dried chickpeas, soak ¾ cup dried beans in cool water for 8-12 hours. Drain, place in a saucepan covered with several inches of water, and add a bay leaf if you like. Simmer the beans until very tender, about 1 hour, adding in ½ teaspoon fine sea salt toward the end of cooking. Measure out what you need for the burgers, saving the rest for another use.Nutritional values are based on one of six burgers.