This recipe by Ed Smith (of Rocket & Squash) hails from The Borough Market Cookbook and is inspired by all the wonderful coffee shops in the market. A shot of espresso intensifies the chocolate in this shortcrust tart. Smith recommends serving the tart in thin slices with a spoon of crème fraîche. You can purchase the book here.

Ingredients

For the pastry:

  • 180g plain flour
  • 150g cold unsalted butter, cubed
  • 30g ground almonds
  • 40g unsweetened cocoa powder
  • 40g icing sugar
  • pinch of flaky sea salt
  • 1 egg, lightly beaten
  • 2 tablespoons chilled water

For the filling:

  • 200g dark chocolate (85% cocoa solids), broken into chunks
  • 300ml double cream
  • 60ml whole milk
  • 60ml (triple) espresso
  • 3 large eggs
  • 150g golden caster sugar
  • 1/2 teaspoon flaky sea salt
  • full-fat crème fraîche, to serve
 

Method

  1. Preheat the oven to 200C fan/220C/gas mark 7.
  2. Start by making the pastry base. Rub together the flour and butter until the mix resembles breadcrumbs—you can do this with your fingertips or a pastry blender in a bowl. Add the ground almonds, cocoa powder, icing sugar and salt and mix until thoroughly combined, then add half the beaten egg and the chilled water and bring the pastry together into a ball. Flatten to form a 2-3cm–thick disc, wrap and refrigerate for 1 hour. After chilling, unwrap the pastry and place it between two large sheets of greaseproof paper then roll it out to a thickness of 3mm. Put it back in the fridge for at least 1 more hour then use it to line a deep, 24cm (9-inch) loose-bottomed tart tin. Chill in the fridge or freezer for 15-20 minutes.
  3. Preheat the oven to 180C fan/200C/gas mark 6.
  4. Cover the chilled, pastry-filled tart tin with greaseproof paper, fill with baking beans or a dried pulse, and bake on the middle shelf of the oven for 10 minutes. Lift the greaseproof paper and its contents from the pastry and bake the pastry for a further 10 minutes. Reduce the oven temperature to 120C fan/140C/gas mark 1. Brush the baked pastry case with the remaining beaten egg and place in the cooling oven for 3 minutes—this will help prevent the base from becoming soggy once filled—then remove from the oven.
  5. You can start to make the filling while the tart crust is blind baking. Place a heatproof bowl over a saucepan of simmering water, making sure the base of the bowl isn’t touching the water. Add the chocolate to the bowl and leave it to melt without stirring. Remove the pan from the heat once melted and set aside (leaving the bowl over the warm water). Put the cream, milk and coffee in a saucepan and bring to the boil then turn off the heat.
  6. Whisk the eggs and the sugar together in a large mixing bowl until light and fluffy. Pour a splash of the hot cream mixture onto the eggs. Beat, then gradually pour the remaining hot cream over the eggs to make a custard. Scrape in the melted chocolate and add the salt. Beat until the custard is smooth and silky (it may seem grainy to begin with but will come together). Set aside until the tart shell is blind baked, covered with a piece of baking parchment to prevent a skin forming.
  7. Once the oven is at the right temperature, place the tart tin on a baking sheet, pour in the custard and bake for 25–35 minutes until it most of the filling is set, with a slight wobble in the very centre. Remove from the oven and leave to cool to room temperature before cutting into portions and serving with crème fraîche.