Place steaks on cutting board, cover with plastic wrap and pound with the flat side of meat mallet to help flatten slightly and tenderize.
Cut steak into 1/3-inch thick strips about 2-inches long. Dab steak dry with paper towels, separate pieces sticking together. Set aside.
In a mixing bowl whisk together chicken broth, shaoxhing wine, soy sauce, rice vinegar, granulated sugar, black pepper, sesame oil and cornstarch. Set aside.
Preheat a 12-inch non-stick skillet over moderately high heat. Drizzle in 2 tsp vegetable oil and add half the steak quickly spreading apart into a single layer with space between pieces, lightly season with salt.
Let sear just about 45 - 60seconds on first side until nicely browned on bottom, quickly turn and let brown on opposite side about 45 - 60 seconds longer. Transfer to a sheet of foil or plate.
Repeat process with 2 more teaspoons vegetable oil and remaining half of the steak.
Add last 2 teaspoons of oil to now empty skillet and leave over moderately high heat. Add bell peppers and saute, only tossing occasionally, about 3 - 4 minutes until slightly tender.
Add in green onions, garlic and ginger and saute 1 minute longer.
Whisk sauce mixture again then pour into skillet. Let cook until it thickens.
Toss in cooked steak. Serve warm.
If needing to cut back on sodium you can use low-sodium soy sauce and unsalted shaoxing wine.
USDA recommends cooking steak to 145 degrees in center for food safety.