margarine, add the chopped mushrooms and cook for 3 minutes. Cut each egg in half lengthways; scoop out the egg yolks with a teaspoon. Mash the egg yolks and blend with the cooked mushrooms. Season to taste. Fill the whites with the mushroom mixture. Slice the rest of the mushrooms and cook in the remaining butter or margarine. Place the sliced mushrooms in a ilat layer in an ovenproof dish, arrange the eggs on the bed of mushrooms and bake for 5 to 10 minutes. Sprinkle with grated cheese and serve immediately.