This is a staple in my late grandmother's famous Chicken Tetrazzini. It's creamy and flavorful even when made with canned chicken stock, so I bet it's a hundred times as good with the juice from a crockpot chicken...
2 tbsp butter
3 tbsp flour
1 cup hot chicken broth
1/3 cup cream
Salt to taste
Melt the butter in a saucepan over medium-low heat. Stir in the flour with a wire whisk, blending until smooth. Cook, stirring constantly, for two minutes. Add the chicken broth, continuing to stir as the sauce thickens. Bring to a boil, lower the heat, and cook two minutes more. Pour in the cream, taste, add salt, taste again, and heat thoroughly. Makes one and a half cups.
The name velouté is the adjectival form of the French word for "velvet." It is excellent on poultry or seafood, and is used as a base for many other sauces, including Allemande and Suprême.