Dissolve yeast in warm water. Add sugar, salt and oil. Mix in enough flour to make soft dough, knead. Let raise.
Mix sausage, onion, garlic, tomatoes, tomato paste, mushrooms, oregano, salt, pepper, let cook and simmer for 30 minutes.
Roll out ½ of the dough to fit 9”x13” glass dish or 11”x17” jelly roll pan. Spread with cheese filling.
Top with other half of dough and the meat filling. Bake at 400° for 15 minutes.
Add topping of ½ lb. mozzarella, ½ tsp oregano, ¼ parmesan cheese and bake an additional 15 minutes.