Step 1

Heat the oven to 180C/fan 160C/gas Unravel the shortcrust pastry sheet and use to line a 20cm tart tin. Press into the sides of the tin and loosely cut around the edges, leaving a little overhanging. Line the pastry with a scrunched-up piece of baking parchment, and fill with raw rice or baking beans. Bake for 15 mins, remove the paper and bake for another 5-10 mins until dry.

Step 2

While the pastry is cooking, put the butter and chocolate into a heatproof bowl set over a pan of just-simmering water and melt together, stirring often. When melted, remove from the heat and leave to cool slightly. Add a pinch of salt if your butter is unsalted.

Step 3

Whisk together the eggs and sugars briefly in a bowl until combined, then stir in the melted chocolate and butter. Sieve over the flour and fold in until just combined. Stir in the orange juice and zest.

Step 4

Trim the edges of the pastry tart with a serrated knife to neaten, and spoon the brownie mixture into the middle. Smooth over with the back of a spoon or spatula, and bake for a further 30-35 mins until the top forms a crust, and the filling is no longer wet but slightly wobbly.

Step 5

Leave to cool for 15 mins before removing from the tin if serving warm, or serve at room temperature. Serve with a dollop of crème fraîche, and some more orange zest grated over. Keeps for 3 days in an airtight container.