I make a rather decent curry sauce for a chicken or pork katsu, i. It would go equally well with a battered sausage.
First sweat the mirepoix in a generous splash of oil. When nicely softened, add flour, cumin, garam masla and curry powder. Cook the spices out, then add the stock and simmer to chieve the desired consistency. Finish with a splash of soy sauce.
You can have that one on me.