Step 1

Pour the double cream into a jug and season lightly with salt and black pepper. Finely chop the tarragon leaves and add them to the cream together with the chopped parsley and dijon mustard.

Step 2

Wash the spinach leaves then, still wet, put them in a deep saucepan and place over a moderate heat, cover tightly with a lid and let the spinach steam for a couple of minutes.

Step 3

Cool the wilted leaves very quickly under cold running water, then squeeze gently dry.

Step 4

Pour the cream into a bowl.

Step 5

Break or tear the hot-smoked salmon into small pieces, about the size of a postage stamp, removing the skin as you go. Check for any bones and carefully remove them, dropping the flesh into the seasoned cream. Add the spinach to the fish.

Step 6

Lightly butter the gratin dishes and place them on a tray then fill them with the salmon, spinach and cream mixture. Sprinkle with the grated cheese and bake at 200C for 20 minutes till bubbling.