1. Pulse first 4 ingredients (through cumin) and 1/4 teaspoon each salt and pepper in a food processor until coarsely chopped and mixture comes together. Transfer to a bowl, add egg and 2 tablespoons flour; form into 8 (1/2-inch-thick) patties. Place remaining flour in a small dish and roll patties in it with floured hands; tap off excess flour.
2. Heat oil in a nonstick skillet over medium-high heat. Cook patties for 2-3 minutes per side or until golden.
3. Whisk together the yogurt, lemon juice, and remaining salt and pepper. Divide greens, tomatoes, onion, and patties evenly among 4 plates; drizzle each salad with 2 tablespoons dressing. Serve with pita chips, if desired.