A mild flavor and delicate but firm texture make cod exceptionally suitable to cook on the stove. A readily available fish, found in both the Atlantic and Pacific oceans, cod can be purchased in most places year-round either fresh or frozen. If frozen, cod should be defrosted before cooking. Prior to cooking, rinse cod fillets under cold running water and pat dry with paper towels.
Set up, assembly-line style, a breading station on your kitchen counter. Working from left to right, set out the uncooked cod fillets; a pie plate one-third filled with cracker or matzo meal crumbs; another pie plate containing egg(s) beaten with 2 tablespoons water for each egg used; and a platter. Sprinkle about 1 tablespoon crumbs on the bottom of the platter.
Working with one cod fillet at a time, use a fork to transfer a cod fillet to the bread crumb plate first. Coat each side with crumbs, using the spoon if needed. Then, transfer the crumb-coated cod fillet to the egg-water mixture, coating each side in the liquid. Then, move it back to the crumbs, coating each side of the fillet with crumbs once more.
Place the breaded cod fillets in one layer on the platter. Do not crowd. Use wax paper, sprinkled with crumbs, between each layer of fillets, if needed. Refrigerate the breaded fillets for at least 30 minutes to allow the breading to adhere well.
Heat the canola or peanut oil, 2 inches deep, in the frying pan on medium-high heat. Drop a small piece of bread into the oil. If the bread sizzles and browns quickly, the oil is hot enough for frying. Remove the cod fillets from the refrigerator. Carefully lower the fillets into the hot oil. Don't crowd the pan. Fry both sides of each fillet until golden brown. Use a fork to test for doneness. When the fish flakes apart easily and is opaque throughout, the fillets are done. Remove the cooked fillets carefully with a heatproof, slotted spoon, and drain on paper towels before serving.