To a food processor, add chickpeas, parsley, onion, garlic, tahini, cumin, salt, pepper and mix/pulse to combine, scraping down sides as needed until thoroughly combined. You want a a crumbly dough, not a paste.
Add flour 1 tablespoon at a time and pulse/mix to combine until no longer wet and you can mold the dough into a ball without it sticking to your hands.
Transfer to a mixing bowl, cover and refrigerate for 1-2 hours to firm up. If you need to skip this step, the falafel will be a little more fragile when shaping and cooking.
Once chilled, scoop out rounded tablespoons and gently form into 11-12 small discs.
Sprinkle on panko bread crumbs and gently press to adhere - flip and repeat.
Heat a large skillet over medium heat and add enough oil to generously coat the pan - about 2 tablespoons.
Once the oil is hot, add only as many falafel as will fit very comfortably in the pan at a time.
Cook for 2-3 minutes on each side, flipping when the underside is deep golden brown.
Repeat with all falafel.