Roasted in all the right ways, this recipe is prime for your favorite grilled cheese. While we recommend an immersion blender to get the perfect puree, you can also easily transfer the hot soup into the blender a few batches at a time, making sure only to fill it halfway to allow for steam.
3 pounds plum tomatoes, halved (about 14 or 15 medium tomatoes)
1 medium-size yellow onion, quartered
6 large garlic cloves, smashed
10 thyme sprigs
2 tablespoons olive oil
1/4 teaspoon black pepper, plus more for serving
1 tablespoon kosher salt, divided
3 cups lower-sodium chicken broth
1 1/2 tablespoons balsamic vinegar
6 ounces sharp Cheddar cheese, shredded (about 1 1⁄2 cups), plus more for serving
Chopped fresh chives
Preheat oven to 425°F. Toss together tomatoes, onion, garlic, thyme, oil, pepper, and 1⁄2 Tbsp. of the salt on a large rimmed baking sheet. Arrange tomatoes evenly, cut side down, on baking sheet. Bake in preheated oven until tomato skins begin to blister, 25 to 30 minutes.
Peel and discard skins from cooked tomatoes; discard thyme from baking sheet. Transfer peeled tomatoes, onion, garlic, and any accumulated juices from baking sheet to a Dutch oven. Add broth, vinegar, and remaining 1⁄2 Tbsp. salt. Process mixture with an immersion blender until smooth, about 2 minutes. Bring to a simmer over medium; simmer 10 minutes.
Remove from heat; stir in cheese until melted and smooth. (If soup is not completely smooth, process once more with immersion blender.) Spoon soup evenly into 6 bowls; sprinkle with additional cheese, pepper, and chives.
