In large soup pot over medium/high heat, saute mushrooms and onions in oil for 5 minutes.
Add chopped garlic and saute 2 more minutes.
Sprinkle in flour, garlic powder, onion powder, Italian season, salt and pepper. Stir to coat Then begin to gradually add in chicken stock, stir between each addition to prevent flour from clumping. Next add pasta sauce. Boil for 15 minutes.
Add tortellini and spinach. Boil according to tortellini package instructions.*
Salt and pepper to taste. Serve topped with shaved parmesan cheese.