Step 1

Sauté the onions and garlic: In a Dutch oven set over medium heat, add the butter. Once it starts to foam, add the onion, garlic, salt, and pepper. Stir until both have softened and are fragrant, about 7 minutes.

Step 2

Make the roux: Add flour. Stir to make a paste. Continue stirring until the flour has taken on a light brown color. Stir and scrape with wooden spoon, 5-7 minutes. The onion paste should look golden with a little brown caramelization.

Step 3

Add tomatoes and stock: Add crushed tomatoes, tomato sauce, chicken stock, and sugar. Stir to combine. Cover the pot and bring to a boil over medium high heat, then reduce heat to medium and let simmer uncovered for about 20 minutes.

Step 4

Purée and serve: Purée the soup with an immersion blender. Alternatively, fill a countertop blender less than halfway with the hot soup. Remove the center lid insert. This allows the hot steam to escape. Cover the hole with a folded kitchen towel and place your hand over the top. Blend. Repeat as necessary until all of the soup has been puréed.Ladle into bowls, topped with freshly cracked pepper, slivered basil, and of course, grilled cheese sandwiches.