Finely dice trout. Halve the eggs and strain the yolks of two eggs through a sieve. Mix the mayonnaise, quark and horseradish together well. Fold in the salmon cubes with dill. Season with salt, pepper and lemon juice.
Toast the bread slices lightly and brush with the trout paste. Chop the remaining egg yolks and whites and place on the toast. Garnish with dill and serve on lettuce leaves.