Wash the chives, dab dry and, except for a little to garnish, cut into fine rolls. Mix crème fraîche, mustard, 1 teaspoon lemon juice and chives. Season with salt, pepper and sugar.
Pluck salad into bite-sized pieces, wash and spin dry. Cut the shrimps in half lengthwise. Wash, quarter, core and cut the pear into 16 slices. Sprinkle pear slices with 1 tablespoon lemon juice.
Toast the bread and cut off the crusts. Spread 4 slices with half of the cream. Spread salad, shrimps (except 4 halved pieces for garnishing) and pears on top. Spread 1 teaspoon of cream on each top layer and cover with the remaining slices of toast.
Halve the toast slices diagonally, place a halved shrimp on top with a wooden skewer. Arrange on a plate with the rest of the chives.