Quick-pickle the carrots: Put the 160 g julienned carrots in a bowl or shallow container. In a small saucepan combine 80 ml rice vinegar, 80 ml water, 25 g sugar and 1/2 tsp salt. Warm over low heat and stir until the sugar dissolves (this step speeds dissolution and gives a glossy brine). Pour the hot brine over the carrots and let cool at room temperature for 15–30 minutes. Why: Quick-pickling brightens the carrots and adds acidity to cut the oil and chili flavors; warming the brine extracts flavor and dissolves sugar so your pickles are ready fast.

Marinate the beef to velvet it: Pat the 600 g thin-sliced beef dry with paper towels (a dry surface sears better). In a bowl combine beef with 1 tbsp tamari, 1 tsp cornstarch and 1 tsp neutral oil; toss to coat and let rest 10–15 minutes. Why: The light cornstarch coating creates a thin velvety barrier that helps the meat stay tender and gives the surface something to caramelize against without steaming.

Preheat your wok or heavy skillet over high heat until very hot — you want it smoking slightly. Add 2 tbsp neutral oil and swirl to coat. Why: High heat is essential for a true stir-fry Maillard sear; a properly preheated pan gives immediate contact heat to caramelize the thin beef quickly rather than stew it.

Sear the beef in batches: Add about one-quarter of the beef in a single layer (do not crowd). Sear 30–45 seconds without moving to get a deep brown edge, toss and stir another 15–30 seconds until just medium-rare through (thin slices finish very fast). Remove to a plate and repeat with the remaining beef, adding the remaining 1 tbsp oil if needed. Why: Cooking in batches keeps the pan hot so each slice browns instead of releasing juices and steaming — this concentrates flavor and gives pleasing texture.

Reduce heat to medium-high and add the minced ginger and garlic to the wok; stir 20–30 seconds until fragrant. Why: Ginger and garlic burn quickly; adding them after the beef prevents bitterness and allows their aromatic oils to bloom in the hot pan.

Add the halved baby bok choy, cut-side down if possible, and a pinch of salt. Let cook undisturbed 30–45 seconds to get a slight char, then toss and cook another 30–60 seconds until stems are crisp-tender. Why: Searing the cut side concentrates sweetness and gives contrast between crisp stems and tender leaves; quick cooking preserves bright color and fresh texture.

Return the beef to the wok along with any accumulated juices. Add the 8 tbsp Szechuan peppercorn oil sauce and toss everything together for 30–60 seconds until well-coated and heated through. Why: Reintroducing the beef at the end prevents overcooking; tossing with the sauce at the last moment prevents the oil from burning while allowing the sauce to coat the meat and vegetables, marrying the flavors.

Stir in most of the quick-pickled carrots (reserve a few for garnish) and taste; adjust seasoning with a little salt or extra tamari if needed. Why: The pickled carrots add sharp brightness — stirring them in at the end ensures the carrots retain crunch and acidity, which balances the oily, spicy sauce.

Finish the dish: Transfer to a warmed platter or plates, sprinkle with the toasted sesame seeds and the reserved pickled carrots for color and crunch. Serve immediately with steamed rice or noodles if desired. Why: Sesame seeds add nutty aroma and a final textural pop; serving hot preserves the contrast between seared beef, crisp bok choy and cool pickles.