Saute ground beef in hot oil until meat loses its pink color. Add tomatoes, tomato sauce, seasonings and mushrooms. Mix well; cook slowly about 2 hours or until sauce is thickened. Cook noodles following directions on package; drain, rinse in cold water and separate. In a buttered 3 litre baking dish make two layers of the noodles, meat sauce, ricotta, slices of Mozzarella cheese and Parmesan cheese, in this order, using about half of each for each layer. Bake in 180ºC oven 30 minutes or until bubbly. Serves 6 to 7. NOTE: Pepperoni may be added to meat sauce if desired. You may double the recipe for sauce; use half in making the lasagne, as above, and serve the remainder, cooked down until quite thick, in a sauce boat along with the lasagne.