Place 1/3 cup flaxseed in a blender or clean coffee grinder, and process until ground to measure 1/2 cup flaxseed meal; set flaxseed meal aside.
Drain chickpeas over a bowl, reserving liquid. Place chickpeas, garlic, and 1 tablespoon reserved liquid in blender; pulse 5 times or until coarsely chopped. Add flaxseed meal, parsley, and next 5 ingredients (parsley through red pepper); pulse just until mixture is combined. Divide chickpea mixture into 8 equal portions, shaping each into a 1/2-inch-thick patty. Combine breadcrumbs and 1 tablespoon flaxseed in a shallow dish. Dip patties in egg white; dredge in breadcrumb mixture.
Heat the oil in a large nonstick skillet coated with cooking spray over medium-high heat. Add patties; cook 5 minutes on each side or until browned.
Line each pita half with a lettuce leaf; fill each pita half with 1 patty and about 3 tablespoons Mediterranean Chopped Salad. Top each with 1 tablespoon yogurt.