Preheat oven to 350°. Brown sausage in a large skillet over medium-high heat, stirring often, 7 to 9 minutes or until cooked; drain on paper towels.
Bring salt and 4 1/2 cups water to a boil in a large Dutch oven over high heat. Whisk in grits, and return to a boil. Cover, reduce heat to medium and simmer 5 minutes or until thickened, whisking occasionally.
Remove from heat; add cheese, stirring until completely melted. Stir in half-n-half milk and next 4 ingredients. Stir in sausage.
Pour mixture into 13×9 inch baking dish.
Bake at 350° for 50 minutes to 1 hour or until golden and cooked through.