Milanese Beef Soup

heat oil in a dutch oven, over moderate heat add beef, brown beef and bones on all sides add onions and saute until softened add carrots, celery, garlic, parsley, salt, basil, and water reduce heat to medium-low, cover, and simmer for 3 hours remove meat and bones discard bones and fat add beef, tomatoes, and potatoes simmer, uncovered, for 30 minutes add beans and zucchini, simmer for 10 minutes add spinach and simmer for 4-5 minutes ladle into a heated tureen or individual serving bowls serve hot, with shredded parmesan cheese to the side