In a large 5-quart Dutch oven, let's start by cooking the sausage over medium-high heat until it turns brown and crumbly, which usually takes around 8 to 10 minutes. Once it's nicely cooked, transfer the sausage to a plate lined with paper towels using a slotted spoon. Don't forget to drain the excess grease from the pot, but make sure to reserve about 1 tablespoon of the flavorful drippings.

Now, it's time to infuse some aromatic flavors into our soup. Saute the onions and garlic in the reserved drippings over medium heat until the onions become translucent, typically around 3 to 4 minutes. This will bring out their natural sweetness and add depth to the overall taste.

Once the onions are nicely sauteed, it's time to introduce the star ingredients. Pour in the beef broth, tomatoes, tomato sauce, carrots, water, wine, basil, oregano, and of course, the cooked sausage. Bring the mixture to a rolling boil, and then reduce the heat to a simmer, leaving it uncovered for a delightful 30 minutes. This simmering process allows the flavors to meld together beautifully.

While the soup simmers, you can skim off any excess fat that may have risen to the surface. Afterward, stir in the zucchini and parsley, and continue simmering the soup, this time covered, for another 30 minutes. This will ensure that the zucchini becomes tender and the flavors meld even further.

To add an extra special touch, we'll introduce the tortellini during the last 10 minutes of simmering. This delicate pasta will cook quickly and soak up the delicious flavors of the soup.

Once the tortellini is cooked to perfection, your Italian Sausage Soup with Tortellini is ready to be enjoyed. Serve it piping hot and savor each spoonful of this hearty, comforting dish that's packed with the taste of Italy.