1) Slice steak thin. In a medium bowl, whisk together soy sauce, rice wine vinegar, corn starch, and red pepper flakes. Add steak and marinate while you prepare other ingredients. Slice garlic and peppers, grate carrot, and whisk together sauce.
2) Cook noodles according to package and when cooked, rinse with cold water to stop the cooking and toss with 1 teaspoon sesame oil.
2) In a large skillet (cast iron or wok) over medium high heat, add neutral canola oil when hot. Add steak slices along with any extra juice from marinade. Cook for 3-4 minutes stirring regularly until steak is cooked through.
3) Add sliced garlic, peppers, carrots, and Arbol peppers (opt.) to the skillet along with all the sauce and cook for 2-3 minutes until sauce thickens and veggies soften a bit (they should still have some crispiness to them).
4) Toss in cooked noodles and stir to combine.
5) Divide noodles and beef between plates and garnish with fresh scallion.