This peanut sauce keeps in a glass container in the refrigerator for weeks. Refrigerated sauce will thicken up considerably. All you have to do is thin it out with a little bit of water to desired consistency, reheat, and serve. The sauce also freezes beautifully. I prefer Maesri red curry paste. But you can also use Mae Ploy red curry paste (it's hotter). A lot of people like to use massaman curry paste, and you can do that too. Originally, Mom used roasted peanuts, ground up in a mortar and pestle. For those who feel the use of natural peanut butter in this recipe is blasphemous, please feel free to go that route. But then, what is unsweetened, natural peanut butter if not roasted peanuts ground up into a paste? For those living in areas of the world where commercial natural peanut butter is not available, please grind up 12 ounces of roasted peanuts using whatever means most convenient for you. Then use the peanut paste in the same manner as peanut butter as directed.