Boil lasagna in pot with 1/8 cup of vegetable oil and teaspoon salt. Cook until tender; drain. Preheat oven to 375 degrees. Put hamburger in fry pan with garlic salt, seasonings, and chop with spatula into small pieces. Brown and add Prego sauce and mushrooms. Stir until hot throughout and slowly bubbling. Line bottom of large baking dish with sauce, then add a layer of lasagna and add layers of the 3 cheeses. Continue layering the lasagna, sauce, and 3 cheeses until dish is filled. Top with the meat sauce and cheeses.
Cover with foil and place in oven for 1/2 to 1 hour or until you seed it bubbling. Then remove foil and bake until top is slightly browned. But be careful not to burn the lasagna.
