Drain and rinse the chickpeas, then pat them completely dry with a paper towel to ensure a crispy texture.
In a food processor, combine the chickpeas, nutritional yeast, parsley, cilantro, garlic, cumin, coriander, sea salt, and black pepper.
Pulse the mixture until it is well combined but still slightly textured, avoiding a complete puree.
Form the mixture into 4 to 5 small, thick patties using your hands.
In a small bowl, whisk together the Greek yogurt, tahini, and lemon juice until the sauce is smooth and creamy.
Heat the olive oil in a non-stick skillet over medium heat.
Place the patties in the skillet and cook for 4-5 minutes per side until they are golden brown and crisp.
Plate the falafel patties and drizzle generously with the lemon-tahini yogurt sauce before serving.