Finely mince the salmon.
In a bowl mix the salmon, the crème fraîche, the juice of half a lemon, the dill and a screw of pepper.
Taste and adjust seasoning with pepper and lemon, then set aside.
In a bowl, mix the fromage blanc and the ketchup; the sauce should be a light pink.
Add more or less ketchup to taste.
Shell the prawns and mix them with the sauce.
Chop the chives and the dill.
Spread a slice with the ketchup cream and place the salad, prawns, chives and Blue Cheese cubes on top.
On a second slice, arrange the salmon rillettes, the dill, some salad, some slices of Mozzarella and a screw of pepper.
Assemble the club sandwich.