Place the rinsed chickpeas, hemp hearts, chickpea flour, parsley, garlic, cumin, salt, and pepper into a food processor.
Pulse the mixture until it forms a coarse meal that holds together when pressed, being careful not to over-process into a paste.
Divide the mixture and shape into four thick patties using your hands.
Heat the olive oil in a non-stick skillet over medium heat and sear the patties for 4 minutes per side until a deep golden crust develops.
While the falafel cooks, whisk together the Greek yogurt, tahini, and lemon juice in a small bowl until the sauce is velvety and smooth.
Serve the hot falafel patties immediately, topped with a generous dollop of the lemon-tahini yogurt sauce.