Begin by cooking the rice noodles according to the package instructions until al dente. Drain and rinse under cold water to stop the cooking process. Set aside.
In a large skillet or wok, heat the sesame oil over medium heat. Add minced garlic and sauté for about 1 minute until fragrant, being careful not to burn it.
Add the sliced bell pepper and snap peas to the skillet. Stir-fry for 3-4 minutes until vegetables are tender-crisp.
Pour in the sweet chili sauce and soy sauce, stirring well to combine. Allow the sauce to come to a gentle simmer.
Add the cooked rice noodles to the skillet, tossing everything together until the noodles are evenly coated with the sauce and heated through. Season with salt and pepper to taste.
Remove from heat and sprinkle the sliced green onions and sesame seeds over the top. Toss gently to mix.
Serve the noodles hot, garnished with fresh cilantro if desired.