01 - Preheat oven to 400°F or heat enough oil in a large skillet for shallow frying.
02 - Season all fish pieces generously with salt and pepper on both sides.
03 - Set up three shallow bowls: one with flour, one with beaten eggs, and one with panko breadcrumbs mixed with cornmeal.
04 - Dredge each fish piece in flour, shaking off excess. Dip into egg wash, then coat thoroughly with panko mixture, pressing gently to adhere.
05 - Fry fish in batches for 2-3 minutes per side until golden brown and cooked through, or bake on a lined baking sheet for 10-12 minutes, turning once halfway through.
06 - Combine mayonnaise, chopped pickles, capers, lemon juice, Dijon mustard, and fresh parsley in a mixing bowl. Refrigerate until ready to use.
07 - Lightly toast slider bun halves for added texture and to prevent sogginess.
08 - Place cooked fish fillet on bottom bun. Top with cheese slice, lettuce, and a generous dollop of tartar sauce. Cover with top bun and serve immediately.