The egg will seal the coating to the food, and the piquant mustard adds a subtle touch. With oven-frying, the skin softens slowly and makes the crust soggy. Removing the skin is not only good for you, but also works best. Using the right pan is essential. There was about 2 inches of space under the racks, allowing air to circulate around the chicken and making the coating more crisp.
Temperature is critical, too.
Cooking chicken at 350 F is typical, but not hot enough for oven-frying, whereas 400 F browns and cooks the crust to a perfect crunch. The technique of oven-frying fish is similar to chicken. We used the same coatings and baking pan with a rack, and a higher temperature of 450 F. Cutting the fish into serving pieces and draining them on a plate lined with paper towels for 10 minutes before cooking delivers a drier surface for the coating to stick to. Softer fillets such as sole and flounder cook too quickly and are too delicate for a crumb coating. Firmer fish such as cod and orange roughy work well.