Drain and rinse the chickpeas, then pat them very dry with a clean kitchen towel to ensure the falafel achieves a crispy exterior.
Place the chickpeas, hemp hearts, parsley, cilantro, garlic, cumin, sea salt, and black pepper into a food processor.
Pulse the mixture until it forms a coarse, crumbly meal, being careful not to over-process it into a smooth paste.
Add the egg whites and chickpea flour to the processor and pulse 3 to 4 more times until the mixture just begins to hold together.
Form the mixture into 6 small, thick patties using your hands, pressing firmly to ensure they stay intact during cooking.
Heat the avocado oil in a large non-stick skillet over medium heat and sear the patties for 4 to 5 minutes per side until they are golden brown and crisp.
While the falafel cooks, whisk together the Greek yogurt, tahini, and lemon juice in a small bowl until the sauce is smooth and creamy.
Serve the warm falafel patties immediately, drizzled generously with the zesty tahini-yogurt sauce.