skewer
Thread pieces of food onto a long, thin stick (metal or soaked wood/bamboo) for grilling or roasting -- lets smaller pieces cook evenly and be turned or removed from heat together.
How to do it
Cut ingredients into reasonably uniform pieces, but more importantly, group ingredients with similar cooking requirements onto the same skewer rather than alternating them purely for looks -- raw chicken, tomato, a thick onion wedge, and zucchini can all need very different cooking times, so separate skewers for meat and vegetables usually give a better result. Leave small gaps between pieces instead of packing everything into one dense cylinder, since that exposes more surface to heat. Wood or bamboo skewers can be soaked beforehand, especially if the exposed ends will sit over high heat.
Common pitfalls
- Mixing ingredients with very different cooking times -- one burns while another is still undercooked.
- Packing pieces too tightly -- the interior surfaces get less heat and less browning.
- Uneven piece sizes -- cooking becomes unpredictable across the same skewer.
- Thin round metal skewers -- food can spin freely around them when you try to turn it.
Why it works
Skewering keeps small pieces convenient to handle while preserving a relatively high surface area, so the pieces cook quickly since heat has less distance to travel to reach their centers. Leaving slight gaps between pieces lets hot air and radiant heat reach more of each piece's surface, improving browning. The skewer itself conducts a small amount of heat inward too, more so if it's metal, though that effect is minor compared to the heat coming from outside.
Equipment
Flat metal skewers are particularly useful because food is much less likely to spin around them, and they're reusable and conduct heat well. Wood and bamboo skewers are inexpensive and disposable but can char -- soaking delays that, though exposed tips may still blacken under intense heat. Choose skewers long enough that a real handle stays outside the hottest part of the cooking zone.