Ingredients

• 1 tbsp olive oil
• 4 small leeks, cut into 1cm/½in pieces
• 1 red pepper, chopped
• 225g/8oz mushrooms, sliced
• 450g/1lb puff pastry, thawed if frozen
• 2 tsp Dijon mustard
• 175g/6oz Cheshire cheese, crumbled
• 1 tsp fresh thyme, chopped (or ½ tsp dried)
• 1 egg, beaten, to glaze
•   seasoning

Method

1. Preheat the oven to 200C/400F/Gas 6. Heat the oil in a frying pan and fry the leeks, pepper and mushrooms over a high heat for 2-3 minutes. Leave to cool a little, tip off any excess moisture and season.
2. Roll out half of the pastry on a floured board to a 25cm/10in square and transfer to a greased baking sheet; spread with the mustard. Roll out the rest of the pastry to a 30cm/12in square.
3. Spoon leek mixture into centre of pastry; scatter over cheese and thyme. Brush edges with cold water, place reserved pastry on top and crimp edges together. Make slits in pastry, brush with egg, then bake for 25-30 minutes until golden.

Notes