Spread mustard sauce on one side of all breads slices.
Place ham on 2 slices. Sprinkle some cheese over these.
Place the ham-cheese bread slices over one another, cover with the third slice.
Pan fry the sandwich with some butter.
In another pan add butter. Break an egg. Fry the egg.
Place the 'sunny side up' egg on the ham and cheese sandwich.
Key Ingredients: Bread, ham, butter, egg, gruyere cheese, mustard seeds