For the pastry

1 Put the flour and butter into a large bowl and rub together with your fingertips until the mix resembles breadcrumbs. Add the icing sugar, lemon zest and salt and mix through.

2 Add the egg yolk, then mix until the dough comes together. Wrap in clingfilm and place in the fridge for 30 minutes.

3 Preheat the oven to 190 degrees (170 fan). Lightly grease a 36cm x 13cm rectangular, loose-bottomed, fluted tart tin and set aside.

4 Lightly dust the work surface with flour, then roll the chilled pastry out into a large rectangle. Line the tart tin with pastry, leaving a little pastry hanging over the edge.

5 Prick the base of the pastry with a fork and place in the freezer for five minutes.

6 Blind-bake the pastry by lining with a piece of parchment paper, filling with baking beans or rice and baking for 15 minutes. Remove the parchment and beans, and bake for a further five minutes, until cooked through.

7 Remove from the oven and trim the overhanging edges of the pastry. Set aside to cool.

8 Reduce the oven temperature to 180 degrees (160 fan).

For the pistachio filling

1 Cream the butter and sugar together in a large bowl until pale and soft. Add the eggs one by one, followed by the almonds and pistachios. Mix well until smooth, then spread the filling into the base of the cooled tart tin.

2 Bake the tart for 30 minutes until puffed up and cooked through. Set aside to cool.

For the rhubarb

1 Cut the rhubarb into batons about 11cm in length. Put the remaining ingredients into a saucepan and bring to a simmer. Reduce the heat to low and add the rhubarb, simmer for about four to five minutes, until the stalks are ever so slightly tender. Remove from the heat and leave to cool in the syrup.

To assemble

1 Remove the tart from the tin and place on a serving plate. Arrange the rhubarb batons along the length of the tart and serve.