Tarte tatin appeared in Lamotte-Beuvron in the late nineteenth century, at a hotel run by the sisters Stéphanie and Caroline Tatin. Legend has it that Stéphanie forgot to put the pastry under the apples, so she threw it on top and then flipped the whole pan over. France's most famous dessert is a mistake nobody bothered to correct.

This version swaps the apples for end-of-season plums. That is not a decorative substitution - a plum has more acid and more water, which means both the caramel and the cooking time behave differently.

Ingredients for a 24-centimetre pan

1.2 kilos of medium red plums, ripe but firm. 150 grams of white sugar. 70 grams of butter. One teaspoon of vanilla extract (optional). A pinch of salt. One teaspoon of lemon juice. One ready-made shortcrust pastry sheet, 230 to 250 grams. To serve: 30 to 40 grams of roughly chopped pistachios, small mint leaves, and crème fraîche, lightly sweetened whipped cream or vanilla ice cream.

Method

Wash and dry the plums, halve them and remove the stones without breaking the halves apart. If they are very large, cut them into quarters. Take the pastry out of the fridge just before you use it - it needs to be cold.

Heat the pan on medium and add the sugar. Let it melt without stirring much, just tilt the pan so it spreads. When it takes on a deep amber colour, take it off the heat and add the butter in cubes. Stir carefully until it is even. Then the salt, the lemon juice and the vanilla.

The lemon here is not for flavour, but for acid that stops the caramel from becoming too sweet.

Arrange the plum halves cut side down, directly onto the caramel, skin up. Pack them in tightly - they will shrink. Fill the gaps with smaller pieces. Keep on medium-low heat for 6 to 8 minutes. The plums will release juice that merges with the caramel. You are not cooking them through - you are only reducing the water until the liquid turns thick and syrupy.

This step is the whole recipe

If the juice stays thin, the tart comes out wet and the pastry does not bake - it boils. If you need to, reduce for another minute or two. This is where a home tatin most often fails, and nowhere in the recipe is it written in capital letters.

Take it off the heat, lay the pastry straight over the plums and tuck the edges down between the fruit and the wall of the pan. Prick the surface with a fork. Bake at 190 degrees, top and bottom heat, for 25 to 30 minutes, until the pastry is golden and crisp.

Take it out and wait 5 to 8 minutes before turning it out - no longer, or the caramel hardens and the tart sticks. Put a large plate over the pan, hold firmly with cloths and flip in one movement. If a plum stays stuck, put it back with a spatula.

Serve it warm, while the caramel is still liquid and the pastry crisp. Pistachios, mint, and a spoon of crème fraîche beside it. If you wait for it to cool so it looks tidier in a photograph, you have lost exactly the thing this dessert exists for.