Toss the prepped vegetables together in a large bowl, then set aside.
To make the dressing, whisk together the peanut butter and oil, then the hot water. Whisk in the vinegar, soy sauce, and Sriracha. Stir in the minced scallions and herbs. Add salt to taste, if desired. If you like a smoother dressing, you can puree all of the ingredients in a blender. If you find the sauce is too thick, just whisk another tablespoon or two of water until the dressing reaches your desired consistency.
Serve the salad and drizzle with as much dressing as you desire, then top with chopped peanuts. The dressing will keep for a week stored in the fridge in a sealed container.