Brown sausage in large skillet on medium-high heat. Drain fat. Set aside. Melt butter in large saucepan on medium heat. Stir in milk and Gravy Mix with a whisk. Stirring frequently, cook on medium heat until gravy comes to boil. Reduce heat and simmer 2 minutes, stirring occasionally. Stir in cooked sausage, cheese and tomatoes. Cook 3 to 5 minutes or until cheese is melted, stirring frequently.