Pan fry sausage, drain, set aside
Add 2 Tablespoons bacon grease to a large pan/pot, let it melt
Add in flour and whisk until slightly bubbly
Add in milk, slowly, whisking and clumps, bring to a simmer and let thicken. If too thick, add more milk. Pepper and salt to taste
Add sausage and stir to distribute evenly into gravy