Make the spaghetti according to package instructions. Drain and set aside.
Add 1 tablespoon of oil to wok or frying pan over medium heat.
Add red pepper flakes and peanuts to oil and stir until peanuts are golden brown and toasted (about 2 minutes).
Remove peanuts and pepper flakes to a plate.
Add another tablespoon of oil to the pan. Add the chicken, cooking for a few minutes on each side, just until cooked through. Remove to a plate to rest.
Add veggies to the pan and saute for 2-3 minutes. Remove to the plate with the chicken.
Slice the chicken into bite-size pieces.
Make the sauce by whisking all ingredients together.
Add sauce to the pan and cook for 2-3 minutes or until it begins to thicken.
Add the cooked noodles to the pan and toss to coat them in the sauce.
Add the stir-fried veggies, chicken, peanuts, and green onion to the pan and toss to combine. Serve immediately.