½ onion,

 diced 1 (4 oz) can sliced mushrooms, 

Salt and pepper (to taste)

½ French baguette, halved lengthwise, or 4 slices of a French bread loaf

 1 c mozzarella cheese,

 shredded Ketchup (to top)

 Instructions: Preheat oven to 400°F. In a large, non-stick frying pan, heat oil. Add onions and mushrooms and sauté for 5 min, until soft. Add a pinch of  salt and pepper. Place baguette halves (or bread slices) on a baking sheet. Top with mushroom mixture and cheese. Bake 10 minutes, until the cheese is melted and golden brown. Top with ketchup to serve.