NOODLES: Cook the ramen noodles 30 seconds - 1 minute less than according to the directions listed on the package. Drain the noodles and set them aside for later (or you can do this while the meat is marinating.)

BEEF: Combine the beef broth, toasted sesame oil, oyster sauce, light brown sugar, soy sauce, minced garlic and red pepper flakes in a small bowl. Stir in the cornstarch until it dissolves. Place the beef in a bowl, drizzle roughly ⅓ of the prepared sauce over the beef and toss to combine, let sit 5 minutes. Heat 1 tablespoon of oil in a large skillet or dutch oven until hot. Add the prepared beef mixture and cook the beef, searing on both sides for roughly 1-2 minutes total. Remove the beef to a plate, set aside.

RAMEN: Add the remaining 1 tablespoon of oil to the pan. Then add the shiitake mushrooms and give them about a 1 minute head start. Add the broccoli and allow it to cook for roughly 2-3 minutes or until the mushrooms brown and the broccoli turns bright green. Pour in the remaining marinade along with the cooked ramen noodles noodles and beef. Toss everything using a pair of tongs and stir to combine and for the sauce to thicken a little bit. Top with toasted sesame seeds if desired and serve immediately.