1. Place chickpeas and onions into the bowl of a food processor and pulse until mixture resembles coarse bread crumbs (5-10 seconds).
2. Add lemon juice, parsley, zest, cumin, salt, and pepper. Pulse mixture until it starts to clump together in the bowl, but before it reaches a full puree (10-15 seconds).
3. Form the mixture into four patties. Heat a non-stick skillet over medium heat and cook, turning once, until patties are golden and crispy on both sides (4-5 minutes per side).
4. Serve inside a whole wheat pita half topped with alfalfa sprouts, diced cucumber, and sliced tomato.