Spray a large pot, and preheat over medium heat. I used an enameled cast iron dutch oven.
Add onions, carrots and bay leaves and continue cooking until veggies are soft, about 5-6 minutes.
Add the garlic, and cook a minute more, being careful not to burn the garlic.
Add vegetable stock, diced tomatoes, tomato sauce, basil and oregano, and bring to a boil.
Reduce heat, partially cover and simmer for 12 minutes, stirring occasionally.
Carefully remove bay leaves. Tongs are helpful for this, but you can also just use a spoon.
Add tortellini and spinach and return to a boil, simmering until pasta is cooked, about 2 to 3 minutes (according to package cook time).
Top each serving with a sprinkle of parmesan cheese, if desired.
