1. Start by slicing the flank steak against the grain into thin strips about a quarter-inch thick to ensure tender bites.
2. Prepare the vegetables by julienning the bell peppers and thinly slicing the onions. Mince the garlic and grate fresh ginger for the aromatics.
3. In a small bowl, make the sauce by combining soy sauce, beef broth, a dash of sugar or brown sugar, and black pepper. Optionally, add sesame oil and rice wine or dry sherry. Mix well and set aside.
4. Heat a tablespoon of oil in a skillet or wok over medium-high heat. Stir-fry the beef strips in batches to avoid overcrowding and ensure even browning. Remove the beef once it’s halfway cooked.
5. Using the same skillet, add the onions, bell peppers, garlic, and ginger. Sauté until the vegetables soften slightly, retaining a slight crunch for balanced texture.
6. Return the partially cooked beef to the skillet with the sautéed vegetables. Pour the prepared sauce over the ingredients and stir to combine and coat evenly.
7. Let everything simmer for a few minutes to meld the flavors.
8. Create a cornstarch slurry by mixing one tablespoon of cornstarch with an equal amount of cold water. Gradually add the slurry to the skillet while stirring continuously to thicken the sauce to your desired consistency.
9. Serve the Best Ever Pepper Steak over a bed of steamed rice or alongside pan-fried noodles for a complete meal.