Chop onion and fry gently in butter, add flour, broth and vinegar, mix well. Peel parsley root and cut into small cubes, add to the soup, bring to a boil and cook until soft, add the cream, whisk blender. Blanch spinach in cream (postpone a part), also whisk. Fry scallops until golden brown on both sides in vegetable oil for about a minute. Fry the spinach leaves in the hot oil. Pour parsley soup on plates, decorate spinach foam, garnish with fried scallop and spinach leaves, sprinkle with salt and pepper.