What is the main base for the Onion soup?

Onion soup traditionally relies on a rich, flavorful base that enhances the depth and heartiness of the dish. The main base for classic onion soup, particularly French onion soup, is often a combination of veal and chicken stock. This mixture provides a well-rounded flavor profile that complements the sweetness of caramelized onions and enriches the overall taste of the soup.

Veal stock contributes a deep, gelatinous quality that adds body to the soup, while chicken stock gives it a lighter, more approachable flavor. Together, these stocks create a robust foundation that supports the other ingredients, allowing the natural sweetness of the onions to shine through.

In contrast, vegetable stock, seafood broth, and lobster stock are not typically used as the main base for traditional onion soup. Vegetable stock might serve as a vegetarian alternative, but it would lack the richness and depth that veal and chicken stock provide, resulting in a significantly different flavor profile that deviates from the classic interpretation of the dish.