Prepare pieces of cling film. Place a stainless-steel ring mould on each one, line it with spinach leaves, then fill with the salmon mousse. Press it down gently with a small spoon.

Cover the top with more spinach leaves. Wrap the whole mould tightly in the cling film, pulling it taut. Ideally the seam should sit on top so no water can get into the mould.

Prepare a water bath: place a steamer rack in a wide pot, then set the wrapped moulds on top. Carefully pour in water so it reaches no more than halfway up the sides of the moulds.

Turn on the heat, but not too high. The mousse needs to poach gently, so keep the water temperature around 80-85°C. Let it cook this way for about half an hour.

Once cooked, remove from the water and let cool. Then unmould, slice, and serve. At this point the mousse will still be warm. You can also let it cool to room temperature and then chill it in the fridge to serve cold.

This mousse also works well for a buffet - arrange all the slices on one large platter and garnish with caviar, lemon slices and dill. For breakfast, serve it with slices of hard-boiled egg; for dinner, try it alongside a spinach salad.