2 tablespoons extra-virgin olive oil
2 large yellow onions, finely chopped
1 tablespoon plus 1 teaspoon kosher salt1⁄2 teaspoon coarsely ground black pepper
1 jar roasted red peppers, rough chopped or pulsed in food processor 5 cloves garlic, minced (about 1⁄3 cup)
4 28 ounce cans whole tomatoes, drained, pulsed in food processor to desired consistency
6 cups chicken stock
2 teaspoons dried thyme
2 large sprigs fresh basil, finely chopped
Sour cream and basil pesto for garnish
Heat the olive oil in a large skillet over medium-high heat. When it is hot, add the onions and 1 teaspoon of the salt. Cook, stirring occasionally, until the onions have softened, about 3 minutes. Add the sliced garlic and continue to cook, stirring, for 3 minutes longer. Transfer the sautéed vegetables to a 6-quart slow cooker and add the tomatoes, chicken stock, thyme, basil sprigs, remaining 1 tablespoon salt and black pepper. Cook on medium-high for 6 hours, stirring occasionally.
When ready to serve, taste and adjust the seasonings if necessary. Ladle the soup into bowls and garnish with a dollop of sour cream and pesto.