Heat about 1/2 inch of oil in a large deep skillet over medium heat (about 350° to 365°). Cut fish in bite-sized pieces. Lightly sprinkle with lemon pepper and garlic salt. Combine pancake mix and bread crumbs in a large plastic food storage bag. Dip fish in a mixture of beaten egg and water. Place fish in bag to coat with crumbs. Fry in hot oil for 7 to 8 minutes, or until golden brown, turning once.
Drain well on paper towels; serve fried fish nuggets immediately with cocktail sauce or tartar sauce.