Bok Choy

Doneness

Done when the leafy tops are charred and tender at the edges while the thick white stems are crisp-tender — the base should give when pierced but still snap, not turn watery and floppy. If the leaves are burning before the stems soften, lay the halves more firmly cut-side down so the stem gets the heat; if the stems are still raw-crunchy, give them another minute or two.

Oil & seasoning

Toss or brush the cut halves with about 1 tbsp oil, getting it down between the leaves. The oil both helps the stems char and weighs the loose outer leaves down so the airstream can't lift and scorch them.

Season with: Garlic-soy-sesame (the benchmark): brushed with a mix of soy sauce, minced garlic, and toasted sesame oil, finished with sesame seeds — the classic stir-fry-greens flavour., Chili-garlic: tossed with chili-garlic sauce or crisp chili oil for a spicy, savoury edge., Ginger-scallion: showered with slivered fresh ginger and sliced scallion over the hot halves, with a splash of soy., Oyster-sauce glaze: brushed with a little oyster sauce (or a vegetarian mushroom-oyster sauce) in the last minute for a glossy, umami glaze — Cantonese restaurant style..

Watch out for

• !Rinse grit out of the stem base before cooking — soil hides between the tightly packed white stalks, and it won't wash out once cooked.
• !Pat the halves thoroughly dry and coat with oil — wet, dry, or loose leaves lift into the heating element in the airstream and char to ash before the stems cook.
• !Keep the halves intact (or quarter a big head) rather than separating into loose leaves — bigger, weighted pieces stay put; stray leaves fly up and burn.
• !Lay everything cut-side down. The thick white stems take longer than the leaves, so they need direct contact with the heat to finish in step with the tops.