Melt 2 tablespoons butter in a skillet over medium heat
Whisk in 2 tablespoons all-purpose flour
Cook for 1 to 2 minutes, whisking constantly
Slowly pour in 1 1/2 to 2 cups milk, whisking until smooth
Cook until the gravy thickens, about 3 to 5 minutes
Add salt to taste
Add black pepper to taste
Stir in more milk if the gravy gets too thick
Serve hot over warm biscuits