Cut the London broil into ¼ inch strips. Pat them dry. In a large mixing bowl, combine half of the soy sauce, black pepper, brown sugar, and red pepper flakes. Add the sliced kosher steaks and mix well. Keep it marinated overnight in the fridge
Slice the onions, bell peppers, and tomatoes. Mince the garlic and ginger. Take a large skillet. Heat 1 tablespoon of olive oil in it. Saute the vegetables for 5 minutes
In the same pan add 1 tablespoon olive oil. Sear the beef steaks for 3 minutes each side. Put them aside
In the same pan put 1 tablespoon of olive oil. Saute ginger and garlic for 1 minute. Mix 2 tablespoons of cornstarch in ½ cup water. Put the slurry in the pan
Add the remaining half soy sauce, salt, pepper, and red pepper flakes. Put the seared kosher steaks and sauteed vegetables into the pan. Mix everything and cook for 5 minutes. Sprinkle roasted sesame seeds on top
