Ingredients:

  • 5 lbs Flank Steak (or Sirloin), sliced thinly against the grain
  • 1 Tbsp Low-Sodium Soy Sauce (for marinade)
  • 1 Tbsp Cornstarch (for velvet texture)
  • 1 tsp Toasted Sesame Oil
  • 1 tsp Freshly Ground Black Pepper
  • 1 large Red Bell Pepper, cut into 1-inch strips
  • 1 large Green Bell Pepper, cut into 1-inch strips
  • 1 medium Yellow Onion, sliced thickly
  • 1 Tbsp Fresh Ginger, minced
  • 2 cloves Garlic, minced
  • 3 Tbsp Vegetable Oil (Canola or Grapeseed), divided
  • 1 cup Low-Sodium Beef Stock
  • 2 Tbsp Oyster Sauce
  • 1 Tbsp Low-Sodium Soy Sauce (for sauce)
  • 1 tsp Light Brown Sugar
  • 1 tsp Rice Vinegar
  • 1 Tbsp Cornstarch mixed with 2 Tbsp cold water (for slurry)

Instructions:

  1. Slice the Steak: Thinly slice the flank steak against the grain into strips approximately ¼-inch thick and 2 inches long. Slicing against the grain is vital for tenderness.
  2. Marinate the Beef: In a medium bowl, combine the sliced beef with all ingredients listed for the marinade (Soy Sauce, Cornstarch, Sesame Oil, Black Pepper). Mix well until the cornstarch coats every strip. Set aside to rest at room temperature for at least 30 minutes.
  3. Prepare the Sauce: Whisk together the Beef Stock, Oyster Sauce, Soy Sauce, Brown Sugar, and Rice Vinegar in a small bowl. Set aside, excluding the slurry ingredients for now.
  4. Prepare Aromatics and Vegetables: Chop all vegetables, ginger, and garlic so they are ready to go (mise en place). This cooking moves fast!
  5. Sear the Steak (High Heat): Heat 2 tablespoons of vegetable oil in a wok or pan over high heat until shimmering (smoking hot). Add half of the marinated beef in a single layer (do not crowd the pan). Sear for 60–90 seconds per side until nicely browned but still slightly rare inside. Remove the first batch immediately to a clean plate.
  6. Repeat Sear: Add the remaining 1 tablespoon of oil and repeat the searing process with the second batch of beef. Remove the second batch and set aside with the first.
  7. Sauté Aromatics: Reduce the heat to medium-high. Add the minced ginger and garlic to the residual oil in the wok. Sauté for about 30 seconds until fragrant—do not burn them!
  8. Stir-Fry Vegetables: Add the sliced onions and both bell peppers. Stir-fry vigorously for 2–3 minutes. The goal is for the vegetables to be crisp-tender (al dente).
  9. Add the Sauce: Give the pre-mixed sauce a quick whisk, then pour it into the wok over the vegetables. Bring the sauce to a gentle simmer, scraping up any delicious brown bits from the bottom of the pan.
  10. Thicken the Sauce: Once simmering, whisk the cornstarch slurry one last time, then drizzle it slowly into the simmering sauce while stirring continuously. The sauce should thicken and become glossy immediately.
  11. Return the Beef: Return all the seared beef strips (and any accumulated juices) to the wok. Toss everything together rapidly for about 30–60 seconds, coating the meat and vegetables in the glossy sauce.
  12. Serve: Remove from heat immediately and serve piping hot, ideally over steamed Jasmine rice.