Grate cheese; set aside. Slice onions, zucchini & mushrooms, On a medium-hot griddle, saute vegetables just until tender crisp in 1 tsp of butter. Remove to a dish until ready to use. In a small bowl, whisk eggs with salt & pepper. Make 2 circles of beaten eggs on griddle. Top each with 1/2 of refried beans, veggies & grated cheese. Carefully fold each omelette in half enclosing filling; add a tiny bit of water to the griddle (in between the omelettes) & cover with a large lid. When omelettes are cooked remove to serving plates & top with the tomato sauce. Serve with warm olive bread.