Prepare pieces of cling film. Place a stainless-steel ring mould on top, 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 firmly closed. Ideally the seam should be 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 higher than halfway up the sides of the moulds.

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

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

This mousse also works wonderfully 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 boiled egg; for dinner, try it with a spinach salad.