Canteen Mushroom Pie, by Cass Titcombe

This recipe, for Canteen mushroom pie, was created by Canteen executive chef and co-founder Cass Titcombe, and forms part of Caterer's sustainability month.

If you're lucky enough to forage for your own wild mushrooms, there's a great native variety waiting. Any edible wild mushroom can be used for this pie - just cut huge ones into bite-size pieces.

INGREDIENTS
(Serves six)

• 4tbs olive oil
• 35g butter
• 1 medium onion, diced
• 100g leeks, diced
• 10g fresh thyme, leaves picked and chopped
• 15g dried porcini, chopped
• 75ml white wine
• 300ml double cream
• 500g mixed cultivated mushrooms, halved or quartered according to size
• 200g mixed wild mushrooms
• 2 garlic cloves, chopped
• 15g fresh parsley, chopped
• Salt and freshly ground black pepper

To finish

• 700g puff pastry
• 1 egg, beaten

METHOD

Heat up 2tbs of the oil and the butter in a saucepan and sweat the onions and leeks for about 10 minutes or until soft. Add the thyme, dried porcini and wine. Simmer for 5-10 minutes until the wine has evaporated. Stir in the cream and cook for a further 5 minutes. Remove from the heat.

Fry off the mushrooms with the garlic in two batches, using half of the remaining oil each time, in a hot frying pan for 3-4 minutes until the mushrooms are lightly browned.

Add the mushrooms with any juices to the other pan. Stir in the parsley and season to taste. Allow to cool completely.

Preheat the oven to 170°C. Butter the inside of a 28-30cm oval pie dish that is at least 8cm deep (or individual pie dishes can also be used). Roll out the pastry on a well-floured board to a thickness of 3mm. Cut out an oval piece of pastry to line the dish. The pastry needs to be long and wide enough to cover the bottom and sides of the dish, with some extra for overhang. Place in the dish, leaving the edges hanging over the sides. Brush the overhang with a little beaten egg. Fill with the cold pie filling. Cut a piece of pastry for the lid - this should be slightly larger than the dish - and lay it over the filling. Dip your fingers in flour and pinch the edges of the lid to the edges of the pastry lining the dish, to seal them together. Trim off excess pastry with a knife.

Cut three or four 1cm slits in the lid, to allow steam to escape during baking. Brush the lid with beaten egg to glaze. Bake for 35-40 minutes until the pastry is golden brown and the filling is bubbling around the edges and through the slits in the lid.

Serve with mash, greens and gravy.