Cook noodles according to package's instructions. Drain and set aside.
In a large skillet whisk together soy sauce, sesame oil, rice vinegar, sugar, and chili paste and bring to a boil.
In a small bowl whisk together cold water and corn starch. Stir into skillet and bring back to a boil, then reduce to medium low heat.
Stir noodles, peanuts, and green onions into the sauce. Serve immediately.
