1. Prepare the fish. Create a breading station with 3 shallow bowls. In one bowl stir together flour, salt, and pepper. In the second bowl, lightly beat the egg whites with a fork so they froth slightly. In the third bowl, place the panko.
2. Spray a nonstick skillet with vegetable cooking spray. Heat over medium-high heat.
3. Dip each fillet first in flour to coat, then in egg whites, then coat with panko. You may need to lightly press the panko crumbs onto the fish.
4. Place coated fillets in the hot skillet. Cook for 3 to 4 minutes per side, until crumbs begin to turn golden. Just before removing fish from the pan, squeeze juice from one lemon half over the fillets.
5. While the fish is cooking, toast rolls. In a small bowl, combine mayo, relish and Tabasco and stir until well mixed. Cut tomato and onion into thin slices. Cut remaining lemon half into 4 wedges.
Source: Hannaford fresh Magazine, January - February 2013