Preheat oven at 350°F. In a large pot or wok, brown meat and onion. Add mushrooms, salt, pepper, paprika and brown sugar. Stir to coat. Stir in the tomato soup and canned tomatoes (or ketchup). Let simmer 5 min. Cook egg noodles according to directions. Drain and add noodles immediately to meat mixture; combine well. Transfer to an ungreased 1.5-L or 2-L casserole dish. Top with equal amounts of shredded mozzarella and cheddar cheeses. Bake uncovered for 30 min.