- Juice of ½ lemon
- 3 tablespoons mayonnaise
- 3 tablespoons Sweet Pickle Relish
- 2 pounds (900 g) fillets of cod or other firm fish
- 2 tablespoons water
- 2 cups (12 oz., 340 g) instant potato flakes
- 2 tablespoons finely minced fresh flat-leaf parsley, mint, basil, or a combination
- ½ teaspoon grated lemon zest
- Kosher salt and freshly ground black pepper
- 2 cups (8.5 oz., 250 g) all-purpose flour
- 2 large eggs
- Grapeseed, canola, or other flavorless oil for deep-frying
- To make the tartar sauce, combine the lemon juice, mayonnaise, and sweet relish in a small bowl. Stir well, cover, and refrigerate.
- Rinse the fish and pat dry. Slice into ½-inch-thick slabs. Make the pieces as uniform as possible so they will cook at the same rate.
- Pile half the flour on the left side of a baking sheet and the other half on the right. Mix the potato flakes, herbs, and lemon zest into the pile on the right. Generously salt and pepper both mounds. In a medium bowl, beat the eggs with the water. Set the bowl in the center of the baking sheet.
- With your left hand, put a piece of fish into the flour on the left side, turning it to coat well, then drop it into the egg wash. With your right hand, turn the fish over and over in the egg wash, then drop into the potato flake mixture. Use your left hand to lift the dry mixture and pat it onto the fish . Keep one hand dry, one wet. Just keep saying that under your breath. Set the coated fish at the edge of the baking sheet and repeat with the remaining fish. When all the pieces have been dredged, put the baking sheet stove-side.
- In a cast-iron or other heavy straight-sided sauté pan, heat 1 inch of oil to 325°F. Crisp the fish, in batches, until well browned on both sides, turning only once, about 4 minutes per side. Drain the fish on paper towels set on a rack and sprinkle with salt.
- Serve piping hot with the tartar sauce and lemon wedges.