Method
1. For the pastry, cream the butter and sugar together until smooth and light.
Beat in the eggs.
2. Fold in the flour and cocoa powder and draw the mixture together to make a
soft dough. Wrap in cling film and leave to rest in the fridge for 1 hour.
3. Set the oven to 180C/gas 4.
4. Roll the pastry out to fit a 23cm tart tin. Cover the pastry with baking
parchment, scatter over enough baking beans to fill the tart, and bake for 20
minutes. Remove from the oven and set aside.
5. For the filling, melt the butter and chocolate together in a bowl set over a
pan of simmering water.
6. In a separate bowl over another pan of simmering water, whisk the eggs and
sugar together until they leave a ribbon trail in the mixture when the whisk is
lifted.
7. Cool the chocolate slightly and fold it gently into the egg mixture.
8. Remove the baking beans from the pastry case and pour the filling into the
case.
9. Reduce the oven temperature to 160C/gas 2 and bake for 15 minutes. Leave to
cool.
10. To make the mint mascarpone, beat the mascarpone in a bowl with the mint
leaves.
11. Serve the tart in slices, with the mint mascarpone.
