*NOTE: Prep time does not include marinating time*

Add both soy sauces, brown sugar and water to a medium bowl and stir to combine.

Pour half of the sauce into another bowl and set aside. (We will be using this when we cook the beef)

Add steak to the other 1/2 of the sauce and marinade for at least 30 minutes or overnight.

When you are ready to cook add sesame oil to a large skillet or wok.

Add in garlic and cook for 1 minute.

Remove steak from marinade and saute for about 1-2 minutes on each side. (You want the pan to be very hot so the steak cooks quickly and browns.

Add red bell pepper and saute for 1 minute.

Add in the reserved sauce and bring to a simmer.

In a small bowl combine cornstarch and water.

Slowly add cornstarch mixture to pan. Continuously stir until sauce is thickened, about 1 minute.

Serve immediately with green onions and sesame seeds for garnish if desired.