Step 1

To make the pastry, tip the flour into a large mixing bowl, season well with salt and pepper. Cut the butter into the flour using a round-bladed knife, then rub the butter into the flour until the mixture resembles fine breadcrumbs. Stir in the Parmesan and poppy seeds.

Step 2

Pour in the ice-cold water and vinegar and mix using a round-bladed knife, then use your hands to bring the dough together into a neat ball. Flatten the dough into a disc, cover and chill for no more than 10 minutes.

Step 3

To make the filling, heat the oil in a frying pan over a low–medium heat, add the onion and leek. Cook, stirring frequently, until softened and starting to caramelise. Remove from the pan with a slotted spoon and set aside on a plate. Add the bacon to the pan, increase the heat to medium and cook until starting to crisp. Set aside with the onion and leek.

Step 4

Roll the pastry out between two sheets of baking paper into a neat circle about 3mm/1/8 in thick and 4–5cm/1½–2in larger all round than a 23cm/9in tart tin. Carefully peel off one sheet of baking paper and turn the pastry into the tart tin. Press the pastry neatly into the corners of the tin, trim off any excess and patch up any cracks with pastry off-cuts. Prick the base with a fork and line with baking paper. Refrigerate for 15 minutes.

Step 5

Preheat the oven to 180C/160C Fan/Gas 4 and place a baking sheet on the middle shelf to heat up.

Step 6

Place a sheet of baking paper over the pastry cake and fill with baking beans. Carefully place on the hot baking sheet and cook for 15–20 minutes, or until the edges of the pastry are pale golden-brown. Remove the baking beans and paper then return to the oven for 3–4 minutes. Brush the inside of the pastry case with lightly beaten egg white to seal any cracks and cook for another minute.

Step 7

Whisk together the whole eggs, egg yolks and cream. Add the chives and season well with salt and pepper.

Step 8

Scatter the bacon, onion, leek, grated Cheddar and peas into the pastry case and pour over the egg mixture. Cook for 25 minutes, or until the filling is set and golden brown.

Step 9

Serve warm or at room temperature with a crisp green salad.