Cook the rice noodles according to package instructions, then drain and set aside.
In a large skillet or wok, heat the vegetable oil over medium-high heat. Add the garlic and ginger, sautéing for about 30 seconds until fragrant.
Add the bell pepper, broccoli, and snap peas to the skillet. Stir-fry for 3-4 minutes until the vegetables are tender-crisp.
Add the shrimp to the skillet and cook for 2-3 minutes until they turn pink and opaque.
Stir in the cooked noodles, soy sauce, oyster sauce, sesame oil, and red pepper flakes (if using). Toss everything together and cook for an additional 1-2 minutes until heated through.
Remove from heat and garnish with sliced green onions and sesame seeds before serving.