Place a large nonstick skillet coated with cooking spray over medium-high heat until hot. Add onion, jalapeño, and garlic; sauté 3 minutes or until onion is lightly browned.
Combine mashed peas, 1 cup whole peas, onion mixture, 1 cup breadcrumbs, rice, flour, egg, and egg white in a bowl; stir well. Divide mixture into 8 equal portions. Shape into 1/2-inch-thick cakes using wet hands. Pat remaining 3 cups breadcrumbs over cakes.
Heat 1 tablespoon oil in a large nonstick skillet over medium-high heat. Add 4 cakes; cook 4 minutes. Carefully turn cakes over; cook 4 minutes or until golden. Repeat procedure with remaining oil and cakes. Serve with Tomatillo-Tomato Salsa. Garnish with cherry tomatoes, if desired.