Add the ground chicken, crushed garlic, chives, scallions, finely chopped spinach, shredded mozzarella, oregano, garlic powder, onion powder, salt, red pepper flakes, and olive oil to a large bowl. Mix with your hands or a fork until just combined. Do not overwork the mixture. Stop mixing the moment everything is evenly distributed.

While the patties are in the freezer add the feta, Greek yogurt, olive oil, garlic clove, dill, onion powder, black pepper, salt, and lemon juice to a food processor. Blend on high for about 60 seconds until completely smooth and silky. Scrape down the sides halfway through and blend again. Taste and adjust salt, lemon, and garlic as needed. Transfer to a bowl and garnish with Aleppo pepper or paprika if using. Refrigerate until ready to serve.

Heat a drizzle of olive oil in a large skillet over medium heat. Remove the patties from the freezer and add to the pan in a single layer. Cook undisturbed for 5 to 6 minutes until the bottom is deeply golden. Flip carefully and cook for another 5 to 6 minutes until the second side is equally golden and the internal temperature reads 165F on a meat thermometer. Do not press down on the patties during cooking. You will squeeze out all the moisture and end up with a dry burger.

Toast the brioche buns cut side down in the same pan with a little butter or olive oil until golden and slightly crispy. Alternatively toast them in the toaster if you are keeping things simple.

Layer butter lettuce and a tomato slice on the bottom bun. Place the cooked chicken patty on top and add the top bun. Cut the burger in half with a sharp knife. Place both halves face down into a generous pool of whipped feta spread on the plate. Serve immediately.