Place the chickpeas, egg whites, hemp hearts, parsley, garlic, cumin, salt, and pepper into a food processor.
Pulse the ingredients until they form a coarse, moldable paste, taking care not to over-process into a smooth puree.
Form the mixture into four equal-sized patties using your hands, pressing firmly to ensure they hold their shape.
Heat the olive oil in a large non-stick skillet over medium heat and cook the patties for 4 to 5 minutes per side until a golden-brown crust develops.
In a small mixing bowl, whisk together the Greek yogurt, tahini, and lemon juice until the sauce is smooth and combined.
Arrange the baby spinach on a plate, top with the warm falafel patties, and finish with a generous drizzle of the lemon-tahini sauce.