Peanut sauce (also called satay sauce) is originally an oriental sauce. It is made from ground peanuts, but peanut butter can serve very well as a substitute. The sauce was originally intended as a sauce for satay (grilled meat on skewers). Since peanut sauce is very well liked, it started to be very common to dress any meat (steak, pork or chicken). But also on French fries, especially if you combine the peanut sauce with mayo or garlic sauce you then have the popular "pataat oorlog" (potato war).