Preheat over to 200C/400F/Gas 7. Sauté the finely diced leek and spring onions together in a little butter until they are soft. Set to one side.

In a bowl, mix the cream cheese, lemon juice, salt and pepper together; check the seasoning and then add the sautéed vegetables to the cream cheese mixture.

Place the puff pastry rectangles on a large board, and spread the cream cheese and vegetable mixture on to each puff pastry piece, leaving a border of about 1" around the edges.

Place a salmon fillet on top of the cream cheese and vegetable mixture, and then cut each long side of the pastry into strips, and then "plait" the pastry strips over each other in a lattice work pattern - see photo. Glaze the Wellingtons with egg and sprinkle some poppy seeds over the top.

Gently place the Wellingtons on to a greased baking sheet and bake in pre-heated oven for 15 to 20 minutes, or until the pastry is puffed up and golden brown.

Serve immediately as a hot supper dish with potatoes and vegetables of your choice; or serve cold with salad - these make great picnic pies, and can be cut into small portions for a buffet.