Prepare noodles according to package, drain and rinse with cool water, set aside.
Preheat a large frying pan or wok over medium heat, add 1 tablespoon of oil to pan. Sauté onions and carrots for 3 minutes, add in peppers and mushrooms and sauté for another 3 minutes. Remove from pan, set aside in a large serving bowl. Add spinach to pan and quickly wilt for one minute then add to bowl, set aside and cover to keep warm.
Drain and reserve marinade from the chicken. Add 2 tablespoons of oil to pan and cook chicken until golden and browned, about 3 to 4 minutes per side and no longer pink inside, remove and add to bowl of vegetables. Reduce heat to medium-low and add remaining marinade to the pan and cook until boiling, about 2-3 minutes. Add the noodles to the pan and stir into marinade to coat evenly, heat through about 2 minutes. Combine noodles with bowl of vegetables and chicken, toss everything together. Divide amongst serving dishes and sprinkle with green onions and sesame seeds.
**TIP** You can substitute any of the vegetables for others that are preferred. You can also change up the protein to beef, shrimp or tofu. Reduce the marinating time if using shrimp.