Ingredients:

  • 1 lb sirloin or flank steak, thinly sliced against the grain
  • 1 tbsp soy sauce
  • 1 tsp cornstarch
  • 1 tsp vegetable oil
  • 2 tbsp oyster sauce
  • 1 tbsp dark soy sauce
  • 1 tbsp coarsely ground black pepper
  • 1 tsp granulated sugar
  • 1/4 cup water
  • 1 tsp cornstarch
  • 1 lb frozen or fresh udon noodles
  • 1 medium yellow onion, sliced
  • 2 cups choy sum or bok choy, chopped
  • 2 tbsp vegetable oil
  • 2 cloves garlic, minced

Instructions:

  1. Slice the beef thinly. In a bowl, toss the beef with 1 tbsp soy sauce, 1 tsp cornstarch, and 1 tsp vegetable oil to velvet the meat.
  2. Whisk together the oyster sauce, dark soy sauce, coarsely ground black pepper, sugar, water, and 1 tsp cornstarch in a small bowl until dissolved.
  3. Rinse udon noodles under warm water to loosen them and set aside.
  4. Heat 1 tbsp of vegetable oil in a wok or heavy skillet over high heat. Add the marinated beef in a single layer and sear for 1-2 minutes per side until a mahogany crust forms. Remove beef and set aside.
  5. Add the remaining vegetable oil to the pan. Sauté sliced onions until translucent, then stir in minced garlic and cook for 30 seconds.
  6. Add udon noodles and choy sum to the pan and stir-fry for 2 minutes until the greens wilt.
  7. Pour in the black pepper sauce and return the cooked beef to the pan. Toss on high heat for 60-90 seconds until the sauce thickens into a glossy glaze.