Eight tomatoes, clean the cucumber and cut into thin slices. Cut the vegetable onion into narrow wedges or roughly dice. Clean the lettuce and pluck it into bite-sized pieces. Finely chop the parsley. Mix together vinegar, salt, pepper, sugar and about 3/4 of the parsley. Beat in 5 tablespoons of oil. Mix the lettuce, tomatoes, onions and olives together. Spread the vinaigrette on top and let the salad steep a little.
Cut the feta into 8-12 pieces. Whisk the egg. First turn the feta in egg, then in breadcrumbs. Heat some oil in a large pan and fry the feta in it for approx. 1 minute on each side. Arrange the feta on the salad and serve sprinkled with the remaining parsley.