I do an Indonesian style satay sauce which is really quick and easy - one of my mum's recipes! - but perhaps not too healthy

I use about half a jar of smooth peanut butter (I actually prefer the low fat one as it has a gritty texture, but use whatever you like, crunchy too I guess!), 4 tablespoons of dark soy sauce, about a mug of boiling water and a teaspoon of ground ginger & one of garlic powder. Heat in a saucepan and keep stirring - add more water or soy to adjust the taste & strength as needed. You can also chuck in something like sambal oelek or chilli powder if you want to give it a kick.
I usually make mine quite thick and serve it over skewers of pork (marinated in soy/garlic/ginger) with a side of spiced egg fried rice & some prawn crackers and sliced cucumber on the side (the dish is called nasi goring with satay babi). You can make it thinner with more water and soy which will bring down the calorie count a bit. I find the amount I make is enough to serve 3.
Thinking about it, I bet you could make one using a traditional indian curry base - boil a few chopped onions (one per person, and then chuck another one or two in

) in water with salt, a bit of curry powder or chilli (probs chilli in this case). When soft and not too much liquid left (at least 30mins) remove from heat and blend into a nice mush. This makes a lovely sauce base and I'm sure if you added a bit of the above recipe to it you'd get a nice textured, flavoursome sauce with far less calories because of the water/onion base.