Combine the egg with a tbsp of mustard - a tbsp of mustard for each egg. Mix until homogenous.
Prepare three plates - flour, the eggs, and the bread crumbs.
Add spices to the bread crumbs - whichever you prefer. Paprika, ground pepper, sesame seeds, and salt are good choices.
Pat dry the food you wish to fry (steak, vegetable, etc).
Cover the deep-fried food with a thin layer of flour, then egg and finely breadcrumbs. Make sure each has a thin layer, discard any excess breadcrumbs or egg.
Place the food in hot oil until it browns. Pat it dry with a paper towel from the oil.
Serve immediately!