Bake in an oven preheated to 175°C for 10–15 minutes, adjusting the time depending on the size of your tartlet shells. The pastry should turn golden but must not get too dark. Remove the shells from the tins and leave to cool completely.

Put the sugar into a large non-stick pot. A wide, shallow pot is ideal, as it lets the sugar caramelize over a large surface area.

Turn on the heat and let the sugar melt slowly over medium, or slightly above medium, heat. Don't turn the heat up all the way, or the caramel will burn.

Once most of the sugar has melted and starts to darken, stir the caramel with a wooden spoon. Don't worry – some recipes tell you not to stir, but it's better to have a few lumps in your caramel (they'll melt away anyway) than to end up with burnt caramel.

Take the pot off the heat and add the butter to the caramel. It will start to spatter, so be careful! Stir it in, then mix in the hot cream. Return to the heat and cook gently together until any remaining lumps have dissolved.

Set the caramel aside for a moment to cool slightly, then season with salt. Start with just one teaspoon, taste, and add more to taste, until the saltiness is just right for your liking.

Spoon the caramel into the cooled tartlet shells, filling them only halfway (a few can be filled all the way, if you like). Chill in the fridge until the caramel has set.

Bring the cream to the boil in a pot on the stove. Remove from the heat and break the chocolate into it. Leave to stand for five minutes, then whisk until you have a smooth chocolate cream. Pour this over the caramel to fill the tartlets the rest of the way.

Decorate the tops of the tartlets with nuts, chocolate, fruit, or whatever you like. They taste best if you let them rest for at least 24 hours before serving.