Preparation Mix 1/4 cup oil and 4 tablespoons tarragon in bowl. Season with salt and pepper. Brush over both sides of bread. Toast bread in large skillet over medium heat until crisp, about 6 minutes per side. Transfer croutons to plate. Meanwhile, heat 1/4 cup oil in another large skillet over medium heat. Add 4 cups tomatoes, next 3 ingredients, and 3 tablespoons tarragon. Sauté until vegetables just begin to soften, about 6 minutes. Stir in tomato paste. Reduce heat to medium-low. Cover; cook until tomatoes and shallots are soft, stirring occasionally, about 10 minutes. Strain soup into bowl, pressing with rubber spatula to extract as much of the juice and solids as possible. Discard solids in sieve. Season soup with salt and pepper. Freeze soup just until cold, about 30 minutes. Ladle into bowls. Top with croutons; sprinkle with 1/4 cup chopped tomatoes.