Chop the basil leaves with a knife. Cut the lettuce leaves or pick them with your hands. Cut the onion into half rings and marinate for 15 minutes : add sugar and vinegar to the water, lower the onion there.
Squeeze the juice out of half an orange. Add mustard and butter. Mix well. Salad dressing is ready. Wash the pear, do not peel it. Cut the pear into thin slices.
Grate the cheese on a fine grater. To the lettuce and basil leaves, add the salad dressing and pickled onion, after draining the excess liquid from it. Mix the salad. Put them on plates. Spread the pear slices over the salad, sprinkle them with cheese and serve.