A simple tomato soup really sings when you rely on good ingredients—but it helps if you’ve got a gooey grilled cheese for dunking.
Allergen Note: Contains milk, wheat.
Open the can of crushed tomatoes and pour them into a saucepan. Swirl the can with 1 cup of water and add to the pan. Add 3 tablespoons olive oil, 2 or 3 cloves of whole smashed garlic, and 1 teaspoon salt. Bring to a simmer over low heat and cook until the tomatoes darken and the garlic is soft, 20 to 30 minutes (see note below). Stir occasionally to prevent scorching. Season to taste with salt.
Meanwhile, build the grilled cheese sandwiches: Thickly slice the country bread for 2 pieces per person, reserving the rest. Lay the slices on the cutting board. Spread with mustard, if using. Thinly slice the Toma, removing the rind, and layer a few slices per sandwich. Press the halves together.
In a large cast-iron skillet over medium-low heat, melt 1 tablespoon butter. Working in batches if necessary, add the sandwiches. Using another clean, heavy pan, gently weigh down and flatten the sandwiches. Cook until fragrant and golden, 5 to 7 minutes. Spread some more butter on the top of each sandwich before flipping and cooking the second side, 3 to 4 minutes longer. Transfer the sandwiches to the board and cut into halves. Repeat with the remaining sandwiches.
Ladle the tomato soup into bowls and grind with pepper. Serve warm, with the grilled cheese sandwiches for dipping.
If you’re in a hurry, you can simmer the soup for 10 minutes, and remove and discard the garlic cloves. But ideally, the garlic softens and cooks down into the soup.