Pre-heat the oven to 180°C/160°C fan/Gas Mark 4

To make the pastry, sift the flour and salt into a bowl, add the butter and rub together using fingertips until the mixture resembles fine breadcrumbs. Add the egg yolk and enough of the chilled water to bring the mixture together to form a dough. Wrap in plastic wrap and rest in a cool place for 20 minutes.

Roll out the pastry on a floured work surface to form a square 28cm x 28cm and line the tin. For easy transfer to the tin, use a large thin-bladed metal turner or palette knife to loosen the pastry from the worktop, roll the pastry around the rolling pin then unroll starting from one side of the tin and finishing at the other.

Press the pastry into the flutes, trim any excess above the tin and prick the base with a fork in several places. Place a piece of scrunched up baking paper inside, large enough to cover the base, and fill with baking beans. Bake blind for 15 minutes, remove the paper and baking beans and return to the oven to for 5 minutes.

For the filling, heat the oil in a frying pan and cook the pancetta or bacon until lightly coloured but not crisp and drain onto some kitchen paper. Combine the eggs, crème fraîche, nutmeg, salt, half the grated cheese and stir in the cooked pancetta.

Spread the remaining grated cheese over the base of the blind baked tart and pour in the filling. Arrange the asparagus spears on top vertically, then horizontally to create 4 quarters.

Put into the oven and bake for 35-40 minutes until the centre is set and the top is golden.

Remove from the tin and slide from the base onto a board or serving plate. Best eaten warm or at room temperature.

Cook's Notes

Readymade butter shortcrust pastry can be used if preferred; you will need around 400g.

For an alternative flavour substitute the cooked pancetta for 200g of flaked hot-smoked salmon.

Keep the asparagus trimmings as they can be used in vegetable soups or stocks.