This is good anytime, so don't save it for breakfast. Use frozen egg whites or fresh. A sprinkling of fresh basil, chives or mint after you have turned the souffle out of the pan.
In a heavy 9-inch prying pan that can go into the oven, melt the butter over high heat. Add the mushrooms, season lightly and cook until the mushrooms become soft but not brown.
3
While mushrooms are cooking, whip the egg whites to soft peaks adding salt and pepper to taste.
4
Arrange tomato over the mushrooms.
5
Quickly fold the cheese into the whites and spread out evenly over the mushroom mixture.
6
Place in the oven and bake for 8 minutes until golden on top.
7
Remove from the oven and run a spatula around the sides to loosen. Flip over onto a plate and serve immediately.