(picture copied from link)
Curry paste is easily found in the grocery store Asian food section in a red and green version. I think one is spicier than the other, but either will work with this peanut sauce. I recommend Jif Natural peanut butter. I am thrilled they finally came out with a product that doesn't contain hydrogenated oils and it as smooth as the original. No clumpy "all natural" peanut butter that is stored in the refrigerator and it is about half the price of some it's competitors.