I thought I had posted a recipe before for peanut sauce, so this will be my updated version, since I can't find the original.
1) Stir-fry together in a small amount of oil, adding things in their appropriate order so items all finish cooking at same time:
*vegetables (e.g., red bell pepper, mushrooms, onions, sugar snap peas)
*seasonings (e.g., chicken bouillon, sriracha powder, thai seasoning blend, salt)
*protein - optional (e.g., chicken, tofu, or shrimp)
If desired, cook the protein separately first, then add back to the vegetables when they are almost done cooking.
2) Meanwhile, get some pasta cooking (spaghetti or any Asian-style noodles). Use water from the boiling pasta if needed to keep the stir-fry items from drying out or burning.
3) Mix in some creamy peanut butter, preferably, natural peanut butter, like "Adams." Taste and add a little bit of brown sugar, if desired, and any other seasonings.
4) Once noodles are done cooking, ladle the noodles into the stir-fry mixture in the wok (or skillet) and mix thoroughly. If too dry, add some of the pasta water. If too wet, let it cook down a bit.
5) Garnish and condiments.....cilantro, sriracha sauce, chopped peanuts, lime wedges, soy sauce, etc.