Make the pastry by blitzing the flour, butter and a pinch of salt together in a food processor until it resembles fine breadcrumbs. Pulse in the egg yolk until a soft dough forms (you may need to add 1/2 tsp or so of water but do this very slowly and gradually). Tip the mixture out and form into a flat disc before chilling for 15-20 mins. Roll out the pastry on a lightly floured surface until 1/2cm thick and wide enough to line a 23cm tart tin (loose-bottomed is easiest). Prick the base all over with a fork and chill for 15 mins.

Heat the oven to 180C/160C fan/gas 4. Line the pastry case with baking parchment and baking beans, then bake for 10 mins. Remove the parchment and beans, and bake for a further 5-10 mins until a light biscuit colour.

Blitz a third of the peas with the crème fraîche, half the feta, double cream and eggs, then pour into a bowl and mix in the remaining peas, feta and all the herbs. Season well with salt and pepper, then pour into the prepared pastry case. Bake for a further 25-35 mins until the filling is set and golden. Leave to cool a little in the tin before removing and serving. Will keep chilled for 24 hours. Can be served cold, or warm through in a low oven. Serve with a green salad, if you like.