Mix mustard and salad cream. Sort the salad, wash and pat dry. Pluck the salad a little smaller if necessary. Select the sprouts, wash and drain well. Wash and thinly slice the tomatoes.
Peel onion and slice or cut into fine rings.
Spread all slices of bread with mustard cream. Cover 4 slices with lettuce, tomatoes, turkey breast, onion and sprouts. Place the remaining slices of bread on top.