Freeze steak for 20 - 30 minutes; when slightly firm, slice thinly across the grain. Meanwhile, mix together peanut oil, oyster sauce, curry powder, and brown sugar; set aside. In a small jar, mix together rice vinegar, fish sauce, sugar, and ginger. Combine thoroughly; taste, adjust vinegar and fish sauce to taste and set aside.

 Heat a wok or large sauce pan over high heat. When very hot, add the beef; cook, stirring constantly, until the beef is just done to your taste. (If it throws off liquid, push the beef up the sides of the wok or remove from the pan and allow water to cook off before finishing cooking beef; you don't want it to steam). Stir in oyster sauce mixture and just heat through; remove beef from pan and keep warm. Add sesame oil and cooked noodles to hot pan; stir to combine. Remove from heat.

 Divide noodles between bowls, top with beef. Garnish as desired; add dressing to taste.