Make It Now:

1. Saute Aromatics: In a large stockpot, heat the oil over medium high heat until shimmery. Add the onion, carrot, and celery. Then, add the red pepper flakes and season lightly with salt and pepper. Stir occasionally until the vegetables are just beginning to brown, about 5 minutes. Stir in the garlic for 30-60 seconds more.
2. Cook Flour: Sprinkle the flour over the vegetables and stir for 1-2 minutes, or until flour is fully incorporated.
3. Add More Ingredients: Stir in the chicken stock, tomatoes, tomato paste, sugar, 3/4 teaspoon salt and 1/4 teaspoon pepper, stirring and scrapping the bottom of the pan for any browned bits (these add flavor).
4. Cook Soup: Bring to a boil, then reduce heat to a simmer and cover partially with the lid. Cook for about 15-20 minutes, or until all the vegetables are very tender, stirring and scraping the bottom occasionally.
5. Blend Soup: Remove from the heat. Use an immersion blender to puree the soup in the pot until fairly smooth. (Or, you can transfer the soup in batches to a large blender. Please be careful during this step! Don’t fill the blender full. Cover the lid with a towel and hold securely while blending so the lid doesn’t pop off. Carefully, return the puree to the pot.)
6. Finish Off: Stir in the butter and half and half. Taste and then season the soup with salt, pepper, and hot sauce to your preference.  
7. Serve: Ladle the soup into bowls and garnish with croutons, fresh shredded Parmesan cheese, and fresh basil, if desired.

Freeze For Later: Full cook and fully cool the soup. Freeze in a freezer container or bag (or in individual servings in mason jars, leaving at least 1 inch of head space) and seal well.

Prepare From Frozen: Thaw in the refrigerator or using the defrost setting in the microwave. Warm over medium-low heat, stirring occasionally.