Squeeze the liquid from the onion with your hand and place onion in a large bowl. Wrap the jicama in paper towels or cheesecloth and squeeze out the liquid. Do the same with the potato. (Russet potatos are more starchy than red potatoes and are preferable for this dish.) Place in the bowl with the onion. Stir in the beaten eggs and sprinkle with flour and salt & pepper. Stir again until combined. Form jicama mixture into 8 cakes.

Heat oil in a large nonstick skillet over medium heat. Add patties, half at a time, and cook until browned, turning once, about 10 minutes. Keep patties hot in a warmed oven until all are cooked.

Combine salsa, sour cream, and cilantro in a small bowl. Place some on skillet cakes and serve remainder on the side.