Heat a large saucepan or Dutch oven over medium heat until shimmering. Add olive oil and butter and heat until oil is shimmering. Add onions and cook until softened and translucent, about 3-4 minutes.
2-6 tablespoons olive oil, 2 tablespoons unsalted butter, 1 medium yellow onion
Add garlic and cook 30 seconds until fragrant and bloomed.
3 cloves garlic
Add tomatoes, chicken stock, salt and pepper; bring to a boil and cook 5 minutes.
2 28 ounce cans whole peeled Marzano D.O.P tomatoes w/juice, 1 14.5 ounce can unsalted chicken stock (about 1¾ cups), 1½-2 teaspoons kosher salt, 1/8 teaspoon freshly ground black pepper
Place tomato/onion mixture in a food processor, blender or use a hand blender to puree. If desired, once pureed, pour the mixture through a wire-mesh sieve and use a rubber spatula to press the mixture through the sieve. This step is optional and optimal is serving the soup to young children. Many young children don’t want any green bits or texture in their soups, so it can be more palatable if very smooth. If your target audience is adults, this step is usually unnecessary.
Place the crushed red pepper flakes, basil, fines herbes and basil in a small cheesecloth bag that has been tightly closed and tied. Place the herb bag in the tomato mixture and bring to a simmer. Cook, uncovered, 15-20 minutes, stirring often.
1/8 teaspoon crushed red pepper flakes, 1 tablespoon dried sweet basil, 1 teaspoon fines herbes blend
If desired, add a drizzle of olive oil to each serving of tomato soup once it has been divided into separate serving bowls.
Serve with chopped fresh basil and cheesy crostini.
Garnish: fresh basil
Enjoy!