In a small bowl, make your beef marinade, combine 1 teaspoon soy sauce, 1 teaspoon sesame oil, and ⅛ teaspoon black pepper to make marinade. Add sliced beef. Set aside
Make the noodle sauce by mixing 100 ml cup water (roughly ½ c.) 2 tablespoon s soy sauce, 2 teaspoons brown sugar, ⅛ teaspoon pepper, and 2 teaspoon sesame oil. Set aside.
Beat the 2 eggs together until frothy and pour into a well-greased pan. Cook into a thin omelet for 2-3 minutes or until set on both sides.
Julienne the carrot, zucchini, mushrooms, onion and egg omelet. Try to cut each in thin strips about 2” long. Set aside. Next, drain sauce of beef and cook in a little oil for 2-3 minutes.
Stir fry each vegetable INDIVIDUALLY, the julienned carrots, zucchini and onions on the skillet over medium with vegetable oil individually, saving the mushrooms for last. Keep the mushrooms dry in the pan for even cooking and texture retention. Add a tiny bit of oil and cook for another minute. Cook each vegetable for 1-2 minutes over high heat. When each of the veggies are each done, remove individually. Cook the marinated beef next. Cook for 3-4 minutes and set the veggies and beef aside.
In a pot, add ½ tsp. salt and bring water to boil. Cook noodles for 4-5 minutes and rinse them right away with cool water to stop the cooking process. Strain the water. Add the noodle sauce to a raised edge skillet or pot and warm until the ingredients are fully combined and bubbly.
Add the Korean sweet potato noodles in the pan, making sure the sauce fully absorbs.
Transfer sauced noodles to serving dish and then toss with the julienned veggies and beef. Garnish with egg strips and sesame seeds or red pepper flakes, if desired. Enjoy warm.