Gradually stir milk into Gravy Mix with a whisk in a medium bowl. Set aside.
Preheat oven to 350°F. Cook sausage in a large skillet over medium heat until cooked through. Drain and return to skillet. Add vegetables and gravy mixture.
Bring to boil over medium heat, stirring frequently. Reduce heat and simmer 2 minutes. Pour into 9-inch glass pie plate. Sprinkle with cheese. Bake 10 minutes. Serve with tater tots.