Into the pan that the ham was cooked in (or use bacon grease if you don't have ham juices), add the butter. Once melted, add 1/4 cup of the flour and whisk to combine. Continue adding flour, whisking constantly, until a smooth paste is achieved. Cook the roux over a medium heat until you get a nice deep golden color, about 3 minutes. Add the milk, whisking the whole time to prevent lumps forming. Cook until thick and season to taste. Serve over biscuits!