Pre-heat the oven to 400F.
Bring a big pot of water to a boil over high heat for the ravioli.
Melt the butter in a saucepan over medium heat. Once the butter is melted, add the flour and stir for about 1 minute. Whisk in the milk and let simmer for about 5 minutes until the sauce becomes thick. Once the sauce is thick, add a pinch of freshly grated nutmeg and a couple of drops of hot sauce, depending on how spicy you like it, to add a depth of flavor to the sauce.