Panna Cotta

Submerge the gelatin sheets one at a time in a bowl of cold water so they don't stick together, and leave them to soften for 5 to 10 minutes. Cold water is essential — warm water dissolves the surface and you lose gelatin. The sheets will go limp and fully pliable. Lift them out and gently squeeze away the excess water; you want the swollen sheet, not the soaking liquid. (For powdered gelatin, sprinkle it over 30g cold water and let it absorb into a firm sponge.)

Combine the cream, milk, sugar, and salt in a heavy saucepan. Scrape the vanilla seeds into the pot and drop in the empty pod. Warm over medium-low heat, stirring to dissolve the sugar, until the mixture is steaming and barely trembling at the edges — about 65 to 75°C. Do NOT boil; panna cotta is cooked cream, not custard, and you only need enough heat to dissolve the sugar and later melt the gelatin. The lower the temperature, the cleaner and milkier the final flavor. Pull it off the heat the moment fine wisps of steam rise and tiny bubbles ring the pan.

Off the heat, lift out the vanilla pod. Add the squeezed gelatin to the hot cream and whisk gently until it disappears completely — it dissolves almost instantly in the warm liquid; if you see any thread or lump, the cream has cooled too far, so warm it briefly. For a tangy panna cotta, whisk in the crème fraîche or yogurt now, once the base has cooled to barely warm so the acid doesn't curdle. Strain the base through a fine sieve into a jug to catch any undissolved gelatin or skin. Let it cool, stirring occasionally, until it thickens to the texture of unset cream and the vanilla seeds stay suspended rather than sinking.

Divide the base among lightly oiled ramekins (for unmolding) or serving glasses. Tap each to settle out air bubbles, then chill uncovered until the surface skins, then cover and chill at least 4 hours, ideally overnight. To unmold, dip a ramekin briefly in hot water, run a fingertip around the rim to break the seal, invert onto a plate and give a firm shake until it drops with a soft slap. Serve cold with macerated berries, coulis, or caramel pooled around the base. The whole point is the wobble: it should tremble like a struck drum, not stand up stiff.