Clean the lettuce hearts and cut into large pieces. Cut the cucumber with the skin into half slices. Cut the radishes into slices or eighths. Quarter or eighth of cocktail tomatoes, depending on their size. Cut the butter cheese into small cubes. Arrange all ingredients decoratively on four plates.
Mix the cream, crème fraiche and mustard together and season with the spices and lemon juice to taste. Pour the marinade evenly over the salad. Pluck the trout fillets into bite-sized pieces, quarter the eggs and arrange on the salad.