I have to say, even though I mostly make my own curries from scratch, Tesco do a rendang paste which is amazing and really good with leftover chicken, some veg bits and coconut milk. One jar is enough for two big curries so I usually do that the day after I have a roast chicken.
I also do a simple a pasta bake - fry onions and mushrooms, add a little flour, add hot stock and cook to make a sauce, add chicken and cooked pasta, stick in the oven. Sprinkle with some breadcrumbs if I have some lurking in the freezer.