IMPORTANT! Always use great caution when puréeing hot liquids. If you have time, allow the soup to cool before blending. Never fill the container more than half full. Cover the lid with a folded kitchen towel and hold it in place before you turn on the blender. The initial surge of the blender's contents can cause the lid to pop open, possibly scalding you if it's still hot, and certainly making a mess of your kitchen.
Preheat oven to 450°F.
Strain the chopped tomatoes, reserving the juices, and spread them on a baking sheet. Season with salt and pepper. Drizzle with 1/4 cup of the olive oil and roast until caramelized, about 15 minutes. Meanwhile in a saucepan, heat the remaining olive oil over medium-low heat. Add the celery, carrot, onion and garlic and cook until softened, about 10 - 15 minutes. Add the roasted tomatoes, reserved tomato juices, chicken stock, bay leaf and butter. Simmer until vegetables are very tender, about 15 - 20 minutes. Add basil and nut/rice milk if using.
Puree in a blender or with an immersion blender until smooth. Serve warm. (Recipe♦923)