Combine ingredients for the marinade into a large bowl. Add the beef strips and toss to coat. Set aside to marinade at room temperature for 30 minutes. You can skip this step, but marinading helps to add so much flavor!
While the meat is marinating, prep the vegetables and sauté. Place a large nonstick pan (or wok) over medium-high heat with vegetable oil. Sauté the vegetables until they reach a tender, yet still crisp, texture - approximately 4-6 minutes. Time will depend on how well done you like your vegetables. If you prefer softer - cook longer. When cooked, transfer to a plate and cover to keep warm.
To the same pan, add 2 tablespoons of vegetable oil. Once heated, add the strips of beef (discard the marinade). Cook, undisturbed, 2 minutes. Turn and allow to sear for another 30-60 seconds. Transfer to the plate with the vegetables and re-cover to keep warm.
To a large glass measuring cup, combine ingredients for the sauce and mix well. Combine the cornstarch and water together separately and then whisk into the measuring cup. Pour the sauce into the same pan over medium heat.
Cook and continuously stir for 6-8 minutes, or until the sauce has thickened and reduced by approximately one-third.
While the sauce is cooking, cook the ramen noodles according to the instructions on the packet. Discard the seasoning packets.
Once you have fully drained the noodles, add them to the pan with the reduced sauce and toss with tongs to coat. Allow the noodles to cook in the sauce for 1 minute before adding the sautéed vegetables and beef back to the pan to rewarm for 2-3 minutes.
Toss the ingredients to thoroughly coat. Garnish with sesame seeds, chopped green onions (scallions) and some red pepper flakes.