Place the chickpeas, egg whites, nutritional yeast, garlic, parsley, cumin, coriander, salt, and pepper into a food processor.
Pulse until the mixture forms a coarse, moldable paste, being careful not to over-process into a puree.
Form the mixture into 6 equal-sized patties or balls.
Place the falafel in an air fryer basket and cook at 375°F for 12 to 15 minutes, flipping halfway through, until the exterior is golden and crisp.
In a small bowl, whisk together the Greek yogurt, tahini, and lemon juice until the sauce is smooth and creamy.
Divide the mixed greens, diced cucumber, and sliced red onion between serving bowls.
Top the greens with the warm falafel and drizzle generously with the tahini yogurt sauce.