Preheat the oven to 200°C, 400°F, Gas 6 and put in a baking sheet to warm.
Rub the butter into the flour with the salt until you have coarse breadcrumbs. Add water a little at a time using a round-bladed knife to mix until the mixture just comes together. Form into a ball, cover with clingfilm and refrigerate for 20-30 minutes.
Meanwhile heat the olive oil in a pan and gently fry the courgettes until soft and lightly gold. Remove from the pan with a slotted spoon and lay on kitchen paper to drain.
Steam the broccoli florets for two to three minutes until just tender. Roll out the pastry and press it gently into a lightly greased flan tin. Prick all over with a fork and bake in the oven on the baking sheet for 20 minutes until pale gold. Spread the courgettes and broccoli florets evenly over the pastry base.
Whisk together the eggs, egg yolk, cream, seasoning and Parmesan then pour over the vegetables. Bake in the oven for 35 minutes or until the centre is just set and the filling golden. Leave to cool.
See more French recipes