For the Ground Beef, Onion and Garlic - In a large pot, add olive oil and butter. Turn the heat to medium and add the onion and garlic. Sauté the onion and garlic for about 4 minutes.
To the pot, add lean ground beef and mix it in with the onions and garlic. (If your ground beef has a bit more fat in it than the lean does, cook the beef in a separate skillet).
As the ground beef cooks, stir and break it apart so there aren't any big pieces or chunks of ground beef.
After it’s thoroughly cooked, turn the heat off and transfer the ground beef mixture to a paper towel-lined plate to absorb any excess grease.
Then transfer the ground beef mixture from the plate back into the pot. If the ground beef is cooked separately, after transferring it on the paper towel lined-plate, transfer it back to the pot with the onions and garlic.
For the Soup - Turn the heat (for the soup pot) back on to medium heat. To the pot with the ground beef mixture, add the carrots, celery, tomatoes, beef broth, water, pepper, salt, and cubed eggplant. Stir.
Simmer the soup on low heat for 40 minutes or until the eggplant turns translucent.
Then add the dry pasta* and chopped parsley.
*The macaroni pasta tastes best when it's cooked al-denti (firm) so when making this soup, don't add the macaroni in it until 25 minutes before serving time. Otherwise, the pasta will continue to cook and turn soft if it's left in the pot to simmer further.
Continue to simmer on low heat for 30 more minutes or until the macaroni pasta is cooked al dente (firm).
Do a taste test and add more salt if needed. Salt really brings out the flavor in this soup.
Serve right away (before the pasta cooks further) while warm and top each serving with grated Parmesan cheese and chopped fresh parsley.