Cook the chow mein noodles according to package instructions. Drain and set aside.

In a large skillet or wok, heat the vegetable oil over medium-high heat. Add the ground beef and cook until browned, breaking it apart with a spatula, about 5-7 minutes. Drain excess fat if necessary.

Add the garlic and ginger to the skillet and sauté for about 1 minute until fragrant.

Stir in the bell peppers and carrots, cooking for another 3-4 minutes until they begin to soften.

Add the cooked chow mein noodles, bean sprouts, soy sauce, oyster sauce, and sesame oil to the skillet. Toss everything together until well combined.

Pour in the cornstarch mixture and stir until the sauce thickens slightly, about 1-2 minutes. Season with salt and pepper to taste.

Remove from heat and stir in the chopped green onions. Serve hot.