Ingredients :

• Semi-salted butter — This is what gives that background of slightly salty flavor that balances the sugar in the pastry. Choose a butter with at least 82% fat content — entry-level butter will make the pastry soft and bland. And take it out of the fridge 30 minutes before: butter too cold, pastry crumbles; butter too hot, pastry sticky. There’s a window, make the most of it.
• Organic lemon — The zest, not the juice. It’s important to use an untreated lemon because you grate the skin directly. Grate it finely — a zest that’s too coarse gives bitter bits in the cream, while a fine zest melts into it and scents without imposing.
• Cornstarch (Maïzena) — It stabilizes the cream and gives it that firm texture that holds when sliced without being gelatinous. Don’t try to substitute it with flour — the result is heavier, with a lingering floury taste. 40g, no more.
• Pine nuts — Technically optional. In practice, they are what create the tart’s visual signature. They brown during baking, taking on an amber tint and bringing a slightly woody and sweet taste. Buy them somewhere with high stock turnover — old pine nuts go rancid easily and you’ll smell it immediately during baking.