Brown sausage in dutch oven or soup pot. Once browned, remove & strain off fat reserving 1 tablespoon.
Add olive oil & 1 tbsp. of sausage drippings & sauté the onions until soft, about 8 minutes. Add the pressed garlic, red pepper flakes, and sauté for 30 seconds more.
Add the chicken stock, diced tomatoes, tomato paste, oregano, basil, pepper, parmesan rinds and salt. Bring to a boil & simmer 10 minutes.
Add the tortellini & sausage back. Continue simmering until tortellini cooked.
Add spinach & stir until wilted. Serve immediately.
