First, dice the onion and mince the garlic cloves. Place a large pot on medium high add a little oil then brown the sausage.
When the sausage is almost cooked toss in the diced onion and minced garlic. You do not add them in the beginning because the water from the onions will slow down the browning of the sausage.
Continue cooking until the onions and garlic are fragrant and softened. Then, add in the tomato paste and cook it by mixing it around with the other ingredients.
Next, pour in the crushed tomatoes and broth. Add in the Italian seasoning and balsamic vinegar.
Bring the pot to a simmer for about 7 minutes then add in the fresh spinach and tortellini pasta. Now, cover and allow to simmer for 5 minutes.
Remove the lid and turn off the heat. Season to taste with salt and black pepper before serving. For a creamy soup add 1/2 cup of heavy cream.