Preheat the oven to 400 degrees.
To make the biscuits, combine flour, baking powder, and salt in a medium bowl.
Stir in mayonnaise and milk until a soft dough forms.
Dust the counter with flour and turn out the dough. If the dough is too sticky, add additional flour.
Roll or pat out the dough and cut out 24 biscuits using a biscuit cutter or juice glass.
Place the biscuits on a baking sheet and bake for 12 minutes.
Meanwhile, in a large frying pan, cook the sausage (if you haven’t already). Remove the sausage from the pan, leaving some of the fat in the pan. Add 1 Tablespoon butter to the pan (or 5 Tablespoons if using venison sausage like I did) and stir until melted.
Make a roux by whisking in 1/3 cup flour.
Continue to whisk in 5 cups of whole milk gradually. Whisk until well combined and no lumps remain. Cook for several minutes or until thick.
Add in cooked sausage and salt and pepper to taste. Add other spices as desired or garnish with fresh herbs (I used rosemary).
Serve over hot biscuits!