In a large bowl, whisk together kung pao sauce, peanuts, cilantro, sweet chili sauce, sriracha (or toban djan sauce). And oyster sauce until well-blended. Set aside.
Deep fry frozen pierogies, in batches, in oil heated to 350 degrees Fahrenheit for 4 minutes or until pierogies are golden brown. Toss pierogies with kung pao sauce mixture until completely coated.