Combine potato and onion; squeeze moisture from potato mixture over a sieve. Lightly spoon the flour into a dry measuring cup; level with a knife. Combine potato mixture, flour, and next 5 ingredients (through egg white) in a large bowl. Divide mixture into 12 equal portions; squeeze out any remaining liquid. Shape each into a 1/4-inch-thick patty.
Heat 1 1/2 tablespoons oil in a large nonstick skillet over medium heat. Add 6 patties; cook 5 minutes on each side or until golden. Repeat procedure with remaining oil and patties.