In a large skillet, melt the butter. Slowly whisk in the flour to form a roux, stirring constantly. Just until it's all been evenly incorporated and the roux's thickened.
Slowly add the half & half, whisking constantly, until that too's evenly incorporated and the mixture's thickened slightly.
Season the sauce with cayenne pepper, Worcestershire sauce, black pepper, and nutmeg.
Add the cream cheese, and stir until well blended. If you prefer it a little thinner, you can add a little bit more Half and Half at this point.
Bring the gravy to a boil, stirring constantly. Reduce heat to a simmer. Add the meat, and stir just until the meat is heated through.
Serve over toast, muffins, pancakes, waffles, rice, potatoes, whatever you like.