Step 1Cook the quinoa: Rinse the quinoa under cold running water. In a saucepan, combine the quinoa and water and bring to a boil. Reduce the heat to a gentle simmer and cook, covered, for 15 minutes. Remove from heat and set aside for 15 minutes. Fluff with a fork. This should make about 4 cups quinoa; reserve any extra for another use.
Step 2In a bowl, whisk together the olive oil, lemon juice, chile flakes and eggs.
Step 3In a separate large bowl, combine the quinoa, cumin, mint, oregano, salt and pepper. Add the wet ingredients and mix until fully incorporated. Fold in the bread crumbs.
Step 4Heat the oven to 350 degrees.
Step 5To form the patties, divide the mixture into 10 equal amounts. Press the mixture into ring molds or large cookie cutters to form the patties. Bake the patties until they are firm to the touch and dry, 14 to 16 minutes (timing will vary depending on the size and thickness of the patties). Remove from heat and set aside to cool. Rewarm in a warm oven before using.
Step 1In a large mixing bowl, toss the tomatoes, cucumbers, lettuce, onions and feta cheese with the olive oil, salt and lemon juice.
Step 2To assemble each burger, spread 1 tablespoon hummus on one side (the “bottom”) of a quinoa patty. Top the patty with 1/5 of the tossed vegetable mixture. Dollop the top of the vegetables with 1 teaspoon of tzatziki sauce and top with a second patty. Repeat to form 5 quinoa burgers. Serve immediately.