Ingredients:

  • lb Flank Steak (very thinly sliced against the grain)
  • Tbsp Soy Sauce (low sodium, for marinade)
  • tsp Cornstarch (for marinade)
  • tsp Vegetable Oil (for marinade)
  • packs (approx. 18 oz) Frozen or Vacuum-Packed Udon Noodles
  • Tbsp Neutral Oil (Canola or Sunflower)
  • cloves Garlic (minced)
  • Tbsp Ginger (freshly grated)
  • medium Yellow Onion (thinly sliced)
  • large Carrot (julienned)
  • cup Shiitake or Cremini Mushrooms (sliced)
  • cups packed Bok Choy or Spinach (roughly chopped)
  • cup Beef Broth (low sodium)
  • Tbsp Soy Sauce (full sodium, for sauce)
  • tsp Dark Soy Sauce (optional)
  • Tbsp Mirin
  • Tbsp Brown Sugar (packed)
  • ½ tsp Black Pepper (freshly cracked)
  • Tbsp Cornstarch (for sauce thickening)
  • Tbsp Cold Water (for slurry)
  • tsp Toasted Sesame Oil
  • Toasted Sesame Seeds (for garnish)
  • Sliced Scallions (for garnish)

Instructions:

  1. Prep the Beef: Toss the thinly sliced beef with 1 Tbsp soy sauce, 1 tsp cornstarch, and 1 tsp oil. Set aside while prepping other ingredients.
  2. Make the Sauce: In a small bowl, whisk together the beef broth, 3 Tbsp soy sauce, dark soy, mirin, brown sugar, and black pepper. Set aside.
  3. Cook the Noodles: Boil the udon noodles according to package directions (usually just 2-3 minutes). Drain immediately and rinse quickly with warm water to remove excess starch, then set aside. Do not overcook.
  4. Sear the Beef: Heat half the neutral oil in a large wok or skillet over high heat until shimmering. Add beef in a single layer (work in batches if necessary to avoid steaming). Sear quickly until browned on the edges (about 1 minute per side). Remove beef immediately and set aside.
  5. Aromatics & Veg: Add the remaining oil to the wok. Sauté the garlic and ginger for 30 seconds until fragrant—don't let them burn! Add onions and carrots; stir-fry for 2 minutes until slightly tender.
  6. Introduce Mushrooms: Add sliced mushrooms and cook until they release their moisture and begin to brown (about 3 minutes). Stir in the bok choy/spinach until just wilted.
  7. Sauce Integration: Pour the prepared sauce mixture over the vegetables. Bring to a gentle simmer.
  8. Thicken: Whisk the cornstarch slurry (1 Tbsp cornstarch mixed with 2 Tbsp cold water) one final time and slowly pour it into the simmering sauce, stirring constantly until the sauce thickens enough to coat the back of a spoon.
  9. Combine: Return the seared beef and the cooked, drained udon noodles to the wok. Toss everything vigorously for 1–2 minutes until the noodles and beef are thoroughly coated in the glossy sauce and heated through.
  10. Finish: Remove from heat. Drizzle with toasted sesame oil. Garnish generously with scallions and sesame seeds before serving piping hot.