Cut the bread into small squares of about half to quarter of an inch. Fry them in oil gently and remove from the pan as soon as they turn golden. Wipe the pan out and put in the butter. In a bowl lightly beat the three eggs. Heat the butter until it hisses. The moment it stops hissing pour in the three beaten eggs and with the back of a fork, scramble them in the hot butter for about a minute until all the egg is cooked. When it looks sort of soft scrambled addd the cheese, sprinkle over the croutons and season. While the middle is still a little moist, fold it with a palette knife or fork and tip it onto a warm plate. The omelette will go on cooking for another 35 seconds to a minute after you have taken it out so unless you like eggy shoe leather, take it out of the pan just before it is cooked. It is a wonderful omelette, slightly soft in the middle, crunchy and cheesy.