Combine soy sauce, broth, brown sugar, garlic, and ginger in a small mixing bowl.
Place half of the mixture in a gallon-sized Ziploc bag, add sliced beef, seal (pressing as much air out as you can). Allow the beef to marinate in as long as time allows (the longer the better but if all you have is 5 minutes, that works)! If you marinate for longer than 20 minutes, marinate it in the fridge.
Add cornstarch to remaining mixture in bowl and stir until smooth, cover and refrigerate until ready to use.
Prepare linguini noodles according to package directions.
While noodles are cooking, heat 2 teaspoons oil in a large skillet over medium-high heat and add steak slices, discarding excess marinade. Stir-fry until just browned, remove steak from skillet and set aside.
Add remaining oil to the same skillet and stir-fry peppers, onion, carrots, and broccoli until onions become clear and soft. Add cabbage and beef to the skillet and cook until cabbage becomes soft.
When noodles are done cooking, drain and toss with beef/vegetable mixture, adding the reserved sauce mixture. Toss until noodles are coated in sauce.
Top with sesame seeds and/or red pepper flakes (optional) and serve immediately.