Slice the chicken breast thinly and season with salt and pepper.
Coat the chicken in flour, dip in egg, then cover with breadcrumbs.
Heat cooking oil in a pan and fry the chicken breast until golden brown.
Cut the hamburger bun in half and toast it.
Spread mayonnaise and mustard sauce on the buns.
Layer the chicken breast, lettuce, tomato, and cheese in that order.
Cover with the other bun to finish.