Cook lo mein noodles according to package instructions and set aside.
Heat vegetable oil in a large pan over medium heat.
Add garlic and cook until fragrant.
Stir in chicken, carrots, and snap peas; cook for 3-4 minutes.
In a small bowl, mix soy sauce, oyster sauce, sesame oil, and sugar.
Pour the sauce into the pan and toss to coat all ingredients evenly.
Add the cooked noodles to the pan and stir until fully combined.
Serve hot, garnished with green onions if desired.