Mix mayonnaise, horseradish and yoghurt until homogeneous. Put quail eggs in boiling water, boil for 3-4 minutes, then pour cold water over them, peel and dry. Remove hard ends from asparagus, boil in salted water for 5 minutes, then pour cold water over them and cut into 3 pieces.
Remove casing from the sausages and then cut them into slices and put on a hot pan. Fry for 5 minutes, stirring occasionally, until slices turn slightly golden brown. Put on a plate lined with a paper towel and set aside to cool. Toss diced bread on the pan with the fat that’s left from the sausages. Fry, stirring occasionally, until the bread is golden brown bread on each side (3-4 minutes). Put toasts on a plate lined with a paper towel. Cut tomatoes into halves.
On a platter put alternately the lettuce leaves (broken into smaller fragments), tomatoes, sausage, toasts, asparagus and eggs. Pour the sauce, then sprinkle with freshly ground pepper.