Melt bacon grease over low heat in a 1 1/2-quart sauce pot. Add garlic and salt and cook for one to two minutes being careful not to brown the garlic. Add milk and broth and increase heat. Bring to a simmer and slowly pour in grits. Lower heat and cook grits for 15 minutes, stirring often.
Add remaining ingredients and stir until cheeses are melted. Serve immediately. Yield: 8 servings