For sauce, in a medium saucepan combine mushrooms, green beans, sweet pepper, water, garlic, salt, and black pepper. Bring to boiling; reduce heat. Cover and simmer about 4 minutes or until vegetables are almost tender, stirring occasionally. Do not drain.
Stir together milk and cornstarch; stir into vegetable mixture. Cook and stir over medium heat until thickened and bubbly. Reduce heat. Cook and stir for 2 minutes more. Add cream cheese, stirring until melted.
To serve, pour the sauce over hot cooked pasta. Serve with tomato wedges. Makes 4 servings.