Place a heaped tablespoon of pâté on each steak and then wrap in a prosciutto slice.
Cut each pastry sheet into 2 squares and brush with a little egg. Place a steak in the centre of each, fold over the corners of the pastry and tuck together to seal.
Place the pastry parcels, seal side down, on a lightly greased baking sheet, brush the tops with a little more egg and top with a sprig of thyme. Bake in a preheated oven, 220°C (425°F), Gas Mark 7, for 12–15 minutes until the pastry is puffed and golden. Serve with sugarsnap peas and roasted new potatoes.