In a large bowl, combine beef and sausage. In a 10- to 12-inch frying pan over medium-high heat, melt butter; add mushrooms, garlic, and onion. Stir often until liquid has evaporated and onion is limp, 10 to 15 minutes. Let cool to warm. Add to meat mixture with bread crumbs, salt, pepper, basil, oregano, tomato sauce, and eggs. Using your hands, mix well. In a 9x13 inch baking pan, pat meat to make level and fill pan evenly. Bake in a 350° oven until meat is no longer pink in center (cut to test), about 1 hour and 5 minutes. Let stand for 10 minutes, then cut into thick slices; or slice after loaf is cool. To serve cold, cover and chill 3 hours or until next day. Makes 8 to 10 servings. Per serving: 383 cal.; 22g protein; 27g fat; 11g carbo.; 750 mg sodium; 123 mg chol. BEEF 19