In a small bowl, add the Beef Marinade Ingredients and stir together, then add the beef strips. Stir in one direction until they become slightly sticky. Set this aside.
In another small bowl, add all the Stir-fry Ingredients, mix together, then set this aside.
For the bell peppers, you are only going to use half of each. Cut each pepper from stem end to the bottom. Set one half of each color aside, and wrap the other halves in plastic wrap and place back in the fridge. Remove the seeds.
Cut each pepper half into strips, set these aside. Cut the onion in half from top to bottom, thinly slice each half and separate the pieces. Mince the garlic.
In a saucepan, add enough water to cover the noodles, bring to a boil, then add the noodles, fresh noodles takes about 3-4 minutes, for dry noodles, cook until just tender. For fresh, just drain, for dry, drain and rinse under cold water.
In a wok, wok pan, or large skillet, heat 3 tablespoons of oil on medium high heat, add the garlic and stir-fry until fragrant. Increase heat to high then add the beef mixture and stir-fry for 30-60 seconds. Remove beef to a bowl, leaving the liquid in the pan.
Add the peppers and onions, stir-fry until until just softened but crisp.
Add the noodles, beef, and Stir-fry Sauce to the pan. Mix together well, remove from heat.
Serve hot, and enjoy.