Smoked salmon in honey-mustard sauce
Rinse and trim the radishes and chop them finely. Mix both types of mustard with the lemon juice and honey. Cut off the tops of the watercress and blend it with the radishes.
Butter the bread slices. Lay the lettuce and salmon onto the bread slices and add a spoonful of the sauce. Serve the remaining sauce alongside the open sandwiches.