Preheat the oven to 400 degrees F. Toss together the tomatoes, 2 tablespoons olive oil, salt, and pepper. Spread the tomatoes in 1 layer on a baking sheet and roast for 45 minutes.
Set a dutch oven over medium heat. Add 2 tablespoons of butter and 2 tablespoons of butter. Heat until it shimmers, then add chopped onions and garlic, and red pepper flakes. Cook onions until onions are soft, translucent, and blond about 5 to 7 minutes. Stirring as necessary to keep from burning or browning too quickly in any one spot of the pan.
After the 45 min roasting, remove the cooked tomatoes from the oven.
To the sautéed onions add the canned tomatoes, basil, thyme, and chicken stock. Add the oven-roasted tomatoes including the liquid on the baking sheet. Bring to a boil and simmer uncovered for 40 minutes.
Use an immersion blender to blend or a blender. I find using an immersion blender the easiest and it also provides the best texture.
Taste for seasonings. Serve warm. Garnish with fresh basil leaves, parmesan cheese and a drizzle of olive oil, if desired. Enjoy!!
Notes
Store this tomato soup in airtight containers in the fridge for up to 4-5 days. When you’re ready to enjoy, reheat it in the microwave or on the stovetop.Roasted tomato soup can be made a few days ahead of time, stored in the fridge. I think it even tastes better as it sits and the flavors have time to blend.To freeze, store in a freezer-safe container for up to 3 months. Thaw overnight in the fridge, then rewarm in a pot on the stove.