01 - Pat fish fillets dry with paper towels. Season both sides generously with salt and black pepper.
02 - Arrange three shallow bowls: place flour in the first, whisk eggs with milk in the second, and spread breadcrumbs in the third.
03 - Coat each fillet in flour, shaking off excess. Dip into egg mixture, then press into breadcrumbs to coat thoroughly on all sides.
04 - Pour ½ inch of vegetable oil into a large skillet. Heat over medium-high heat until oil shimmers and reaches 350°F.
05 - Fry fillets in batches for 3-4 minutes per side until golden brown and internal temperature reaches 145°F. Transfer to wire rack to drain.
06 - Combine mayonnaise, Dijon mustard, pickles, capers, lemon juice, and parsley in a small bowl. Season with salt and pepper. Mix thoroughly and refrigerate until serving.
07 - Plate fried fish immediately with chilled tartar sauce on the side. Garnish with lemon wedges if desired.