12 large field or portobello mushrooms, stalks removed
2 tbsp olive oil, for frying
½ onion, finely chopped
100g mushrooms, finely chopped
1 garlic clove, crushed
1 egg, beaten
50ml milk (or almond milk)
2 tbsp ground almonds
100g mixed nuts, finely chopped
50g cooked spinach, squeezed and chopped
1 tbsp each of tarragon, chives and parsley, chopped
500-600g frozen puff pastry sheets
Salt and black pepper
150g blue cheese, chopped
6 tsp cranberry sauce
1 egg, beaten, for glazing
1 Set the oven to 160C/325F/gas mark 3. Put the large mushrooms on a baking sheet, drizzle with a little olive oil and season. Bake for about 15 minutes, then set aside to cool on kitchen roll, to remove any excess moisture (as this will make pastry soggy).
2 Fry the onions for 5 minutes, add the chopped small mushrooms and garlic, then cook over a high heat for another 5 minutes, until tender and all the liquid has disappeared. Allow to cool.
3 In a large bowl, mix the egg, milk, almonds, nuts, spinach and tarragon until well blended. Season. Turn up the oven to 200C/400F/gas mark 6.
4 Lay out the pastry sheets on a floured surface. Cut out 12 discs at least 1cm larger than the mushrooms all the way round. Place a mushroom cap-side down on six of the discs, then spread each with a layer of the spinach mix. Sprinkle with blue cheese and top with 1 tsp of cranberry sauce. Top with the rest of the spinach nut mix and top with the other mushrooms cap-side up.
5 Brush around the edges with beaten egg and put the remaining pastry discs on top of the mushroom parcels. Press down the edges, so they seal with the discs below, and crimp to seal. Transfer the six parcels to a baking tray lined with parchment. Glaze with the egg wash. The rounds can be scored lightly with a knife going down the sides from top to the edges. At this point, you can put them in the fridge and cook them the next day, if you like.
6 Bake for 25 minutes, or until golden.