Heat 1 tablespoon oil in a large cast iron or stainless steel skillet over medium-high heat. Once hot, add the bell peppers, carrots and white parts of the green onions and stir fry 2 minutes. Add the snow peas, garlic and ginger, and stir-fry for 1 minute. Add a splash of additional oil if needed.
Add the sauce to the skillet, stir to combine and bring to a simmer for 1 minute.
Add noodles and toss until evenly coated and warmed through, approximately 1 minute; remove from heat
Add the meatballs and green onions and toss to combine. Garnish with sesame seeds if desired.