Wash the dill and chives, dab dry and chop finely, except for some dill for garnishing. Wash the lemon thoroughly and grate some peel (1 pinch of knife) finely. Mix chopped herbs, lemon peel and crème fraiche. Season to taste with salt and pepper. Put a dash of crème fraîche on each of the crackers and Tucs.
Divide the prawns between the tucs and put 1/2 teaspoon of trout caviar on each cracker. Wash and quarter the cherry tomatoes. Garnish the canapés with tomatoes and dill and sprinkle over them. Arrange on a plate with lemon wedges