Mini mushroom wellingtons

Preheat oven to 200°C (180°C fan) mark 6. Put wild mushrooms in a bowl and cover with boiling water. Soak for 20min, then drain. 

Meanwhile, remove stalks from Portobello mushrooms. Arrange caps on a baking tray (domed side up) and brush each one with oil. Scatter over thyme and season. Roast for 15-20min until tender when tested with a knife. Drain on kitchen paper and let cool.

In a large pan of boiling water, cook kale for 5min. Drain well and return empty pan to low heat. Add butter and fry shallots for 5min. Add garlic and cook for 1min, then stir in drained kale and cook for 2-3min to remove excess moisture. Roughly chop rehydrated mushrooms and stir into kale mixture with walnuts. Check seasoning; set aside to cool. 

Line two large baking trays with baking parchment. On a lightly floured surface, roll one sheet of pastry thinner to a rectangle 25.5 x 35.5cm (10 x 14in) for the bases, then roll the other sheet thinner to 28 x 38cm (11 x 15in) for the lids. Cut both sheets of pastry into 6 equal squares. Cut cheese into 6 equal pieces, slicing in half if some are very thick. 

Divide kale mixture between the smaller squares of pastry, leaving a 2cm (¾in) border, then top with cheese. Add a Portobello mushroom (domed side up) and press down. Brush pastry borders with beaten egg and put lids on, carefully pushing down around the sides. Press edges to seal, then crimp with a fork. Trim edges to neaten, and brush all over with egg. Cut a hole in top of each. Transfer to baking trays and chill for 20min. 

Turn up oven to 220°C (200°C fan) mark 7. Cook for 25min until golden. Serve with seasonal veg or green salad.