tomatoes, cored, seeded and halved
basil, fresh chopped
Preheat broiler and spray a baking sheet with nonstick cooking spray.
Place tomatoes on the baking sheet, cutside down; broil until skins are blistered, about 10 minutes.
Set aside to cool; slip off skins and chop coarsely.
Meanwhile, in a medium-sized saucepan, heat oil over medium-low heat; add onions and saute for 5 minutes.
Add garlic and saute until the onions are very soft, about 5 minutes longer.
Stir in tomatoes and cook, stirring, for 1 minute; transfer the mixture to a food processor or blender and process until smooth, then return to the saucepan.
Stir in stock and bring to a boil; reduce heat to low and simmer for 5 minutes.
Remove from heat and stir in basil; season with salt and pepper.
Cover and refrigerate until chilled, at least one hour - The soup can be stored, covered, in the refrigerator, for up to 2 days.