Shrimp

Shrimp cook fast, and that speed is the whole story. Bite into a raw one and there's no fat to speak of, no marbling to melt and soften things for you — just lean, firm, sweet-tasting flesh from end to end. That means shrimp go from raw to overcooked quickly, so don't wander off while they're on the heat. Watch the colour at the thickest part, not the clock: shrimp turn from translucent grey to opaque pink-white, and the moment that change finishes, they're done. Touch is a clue too — springy and firm means tender, tight and stiff means you've gone too far.

When choosing them, trust your nose before your eyes. Fresh shrimp smell faintly of the sea, clean and mineral. An ammonia smell means spoilage, no matter how firm they look in the tray.

Some people say small shrimp cook just as slowly as big ones. No! Size matters, because heat has to reach the centre, and a jumbo shrimp is simply thicker than a small one. Treat every batch by its own size, not by habit, or you'll either undercook the big ones or turn the small ones into chewy little erasers.