2 (15 oz) cans diced tomatoes
1 (10 oz) can tomato sauce
1/4 cup fresh basil finely chopped
2 cloves large garlic, minced
1 tbsp salt
1 tsp pepper
1 onion, diced
1 cup heavy cream
4 cups chicken broth or vegetable stock to make it vegetarian
2 cups Parmesan cheese, shredded
For the Roux:
3 tbsp butter
1/4 cup flour
1 cup heavy cream or half and half
Add tomatoes, tomato sauce, garlic, onion, basil, salt, pepper, heavy cream, and vegetable or chicken broth to your crockpot. Cover and cook on low for 6-8 hours (although it can be done on high for 2 hours as well). Stir occasionally and scrape down the sides, if you can.
Forty minutes before serving, transfer soup to blender or food processor and puree until smooth. Return to crockpot.
Make your roux by melting your butter in a saucepan over medium heat. Once butter is melted, add the flour and whisk until it's incorporated. Slowly whisk in the heavy cream until the cream is smooth and thickened.
Add Parmesan cheese and roux to the cockpot and stir to combine.
Cook for another 20-30 minutes. Cheese should be completely melted into the soup. Stir thoroughly before serving. Garnish with additional Parmesan cheese and basil, desired.