Gather the ingredients for the soup. Dice the onion and press the garlic.
In a soup pot preheated with a tiny bit of oil over medium heat, add in the ground Italian sausage, breaking it up as you cook it. Next, add in the diced onion and pressed garlic. Cover with 5 quarts of water.
Let the soup simmer for about 20 minutes. Then, add the tortellini and let it simmer until the pasta is cooked through (about 2-3 minutes if you're using refrigerated, raw tortellini and about 5-6 minutes if you're using frozen tortellini). Add in the whipping cream and stir to combine.
Bring the soup to a simmer and add in the diced spinach. Season to taste with salt.