Using two forks, shred the cooked tilapia.

In a large bowl, combine the shredded tilapia, 1/2 cup panko breadcrumbs, potato, eggs, sour cream, lemon juice, chili powder, salt, pepper, and cayenne. Mix well.

Lay out two large plates. Sprinkle the remaining 1 cup panko breadcrumbs on 1 plate.

Using your hands, scoop up a golf ball sized amount of the fish mixture. Roll it into a ball and flatten. Dip it in the panko on both sides and place on the empty plate. Continue with the remainder of the fish mixture.

Heat 2-3 tablespoons olive oil in a large skillet over medium heat.

Working in batches, arrange your fish cakes in a single layer in the skillet and cook for 3-5 minutes, until golden brown. Flip and cook on the other side. Add more oil, as needed.

Cook the remainder of the fish cakes and serve with sour cream.