Trembling Panna Cotta

A panna cotta lives or dies on its wobble - too much gelatine and it turns rubbery, too little and it slumps. For a soft, trembling set, keep the gelatine restrained and calibrated to the volume of liquid (around 6 g of platinum leaf gelatine sets roughly 800 ml to a gentle wobble). Bloom the leaves in cold water until floppy, squeeze out the excess, and whisk them into a hot - but never boiling - base until fully dissolved; boiling after the gelatine goes in weakens its set. If the result comes out firm, ease back by half a leaf next time rather than adding more. The goal is a custard that just holds its shape and quivers when the plate is moved.