Bring a large pot of water to a boil and cook the lo mein noodles according to package instructions.
Drain the noodles and rinse under cold water to stop the cooking process.
In a large skillet or wok, heat the vegetable oil over medium-high heat.
Add the minced garlic and sauté for 30 seconds until fragrant.
Add the sliced bell peppers and carrots. Stir-fry for about 3 minutes.
Add the broccoli florets and continue to stir-fry for another 2 minutes.
Push the vegetables to one side of the skillet and add the noodles to the other side.
Pour the soy sauce and oyster sauce over the noodles and vegetables.
Toss everything together until well combined and heated through.
Drizzle with sesame oil, sprinkle with green onions, and serve immediately.