Which soup is not traditionally served as a main dish?

Tomato soup is typically considered a starter or accompaniment rather than a main dish. It is commonly served before the main course or alongside a sandwich, making it a light, comforting option that sets the stage for the meal. Its primary role is to enhance the dining experience, often highlighting flavors that complement heavier dishes.

In contrast, other soups listed, such as Red Bean Soup, Firehouse Chili, and Tortilla Soup, are often hearty and substantial enough to stand alone as main courses. These soups contain more robust ingredients and are typically prepared to be filling, providing enough nutritional value and substance to be classified as a meal on their own.