Blanch the vegetables: Bring a large pot of water to a boil, add a pinch of salt and 1 teaspoon neutral oil.
1 small bunch Chinese broccoli
Cook for 10–15 seconds, just until bright green and crisp-tender. Don’t overcook.
Pour enough oil into a large pan to coat the bottom in a 2–3 cm layer. Heat to 120–140 °C.
cooking oil
Lay the beef slices in a single layer. Sear for 5–10 seconds, then stir gently until they just change color.
As soon as the beef turns opaque, scoop it out, leaving about 1 tablespoon of oil in the pan. Reserve the rest for another stir-fry.
Add the garlic and Sa Cha sauce and sauté over medium heat for about 30 seconds, until fragrant.
3 cloves garlic, 2 tablespoons Sa Cha sauce
Return the beef to the pan and toss for 1–2 minutes to coat.
Serve the beef with the blanched greens alongside.
Notes
The exact amount of oil isn’t critical, but it really improves the texture, especially if you’re new to this dish or still mastering heat control. For the final photo I’d already cooked several rich dishes, so—as you can see—I went a little lighter on the oil.