Ingredients:

150g mushrooms

40g butter

Salt and pepper

Squeeze of lemon juice

100g cream cheese

3 tbsp finely grated parmesan

Small bunch of chives, snipped (about 3 tbsp)

1 sheet of puff pastry, preferably all-butter

100g lean ham

1 scant tsp Dijon mustard

150g mozzarella, drained

1 egg, beaten, to glaze

Black and white sesame seeds, to garnish (optional)

Method:

Turn the oven to 220C/200 fan/425F/Gas Mark 7. Put in a baking sheet to heat up.

Finely chop the mushrooms. Melt the butter in a pan, add the mushrooms, sprinkle with a little salt and pepper and fry on a low to medium heat until all the moisture has been driven off and they’ve taken on a tinge of colour. Stir in a squeeze of lemon juice, tip onto a plate lined with kitchen paper and leave to cool.

Put the cream cheese in a bowl, add the grated parmesan and snipped chives, season with salt and pepper and mix well.

On a lightly floured surface, roll the pastry into an oblong 36cm x 30cm, then with a sharp knife cut it into two 18cm x 30cm rectangles, making sure the edges are neat. (This is a guide: the exact size depends on your sheet of pastry but remember it’s meant to look like a shutter.) Put one half in the fridge for now, wrapped.

Place the remaining piece of pastry on a sheet of baking paper and lightly mark a 2cm rim all around. Smooth the cream cheese mixture over the inner rectangle and arrange the ham on top, folding where necessary.

Smear the mustard thinly over the ham and add a layer of mushrooms. Tear up the mozzarella and scatter over. Egg wash the pastry rim.

Take the second piece of pastry, dust lightly with flour (crucial, or it’ll stick together) and fold it loosely in half lengthways. Make a series of horizontal cuts through the fold, about 1.5cm apart, leaving a 2cm border on the other three sides.

Without unfolding it, place it on the filled rectangle so that one long edge and the two short edges align. Unfold it to cover the filling and press down the edges, then crimp with the tines of a fork.

Brush with egg wash, scatter with sesame seeds, if using and put the pie in the oven. Cook for 20 minutes then reduce the heat to 180C/160 fan/350F/Gas Mark 4 and cook for another 10 minutes or until the pastry is puffed, cooked through and golden. Serve warm, while the mozzarella is still gooey.