Rinse the spinach well, cut out thick leaf veins, blanch in salted water, rinse when cool and rub dry well. Cut the salmon fillet into thin slices.
Butter two souffle dishes, place spinach and salmon in layers, seasoning the layers repeatedly with a pinch of salt and pepper. Poach the flans in a water bath for about 15 minutes.
In the meantime, sauté the shallot in a saucepan with butter. Add white wine and fish stock and reduce by half. Finally, fold in whipped cream, season the sauce and blend well with a hand blender.
Remove the salmon and spinach flans from the ramekins, serve and pour the sauce over them. Serve with boiled potatoes.
Tip: Did you know that one bowl of spinach already covers the entire daily requirement of vitamin K and beta-carotene?