Add thinly sliced beef to a large storage bag (or container of your choice) along with cornstarch and two teaspoons of soy sauce. Let marinate for 30 minutes.
Prepare noodles according to package instructions, and set aside.
Prepare the sauce by mixing soy sauce, oyster sauce, chili paste, and brown sugar together.
Heat oil in a large skillet over medium high-heat and saute beef until almost cooked through, then remove and set aside.
Add carrots and additional oil if needed, saute for 1-2 minutes, add garlic and ginger, cooking for an additional 1 minute. Then add remaining vegetables, seasonings, and sauce. Cook for 1-2 minutes, or until vegetables are heated and beginning to soften and sauce has reduced slightly.
Add beef and noodles to the skillet and toss all ingredients to ensure they are heated through and combined.