In a 2 or 3 quart saucepan, mix all sauce ingredients except cornstarch/water together, add the frozen meatballs, bring to a simmer, and cook 10 minutes (uncovered). Mix the cornstarch with water and mix into the sauce. Simmer 2 more minutes.
Boil water and cook Ramen noodles for 2 minutes. drain and rinse them.
Meanwhile, heat oil in a wok or large skillet over medium-high heat and stir fry until crisp tender, about 2-3 minutes.
Add the cooked noodles and meatballs/sauce to the vegetable skillet. Toss until all the noodles and vegetables are coated in the sauce. Sprinkle with the green onions, more red pepper flakes, and black pepper.