Look into recipes of classic French cuisine ... too: Mustard turns espagnole into Robert sauce, whereas adding peppers, onions, tomatoes, and Creole seasoning will make sauce Africaine.

In complex, multi-layer dishes like lasagna or potato au gratin ... Espagnole Is A Darker, More Complex Sauce Although Espagnole (or Spanish sauce) starts with a roux, like béchamel and velouté ...