French onion soup dates back to medieval Europe, but the 1651 milk‑based version highlighted by Max Miller reflects the early modern French palate before beef broth became standard. It was reputedly a favorite of King Louis XV, showcasing the era’s love for slow‑cooked, richly flavored dishes.

The historic recipe simmers caramelized onions in milk rather than beef broth, and it omits the melted Gruyère cheese topping that became popular in the early 20th century. Instead, a toasted baguette slice sits at the bottom of the bowl, absorbing the milky broth.

Milk was a common, readily available dairy product in 17th‑century France and provided a creamy, slightly sweet base that complemented the deep caramel flavor of the onions, predating the later shift to meat‑based broths for richer umami.

It was often served as a warming starter during winter banquets and hunting feasts, especially after long hunts when the king and his retinue needed a hearty, comforting dish to replenish energy.

In the Alsace region, a wine‑based version adds white wine; in Provence, herbs like rosemary replace thyme; and in some northern provinces, the soup was traditionally finished with a slice of stale bread soaked in the broth rather than a baguette.

The original called for yellow onions, butter, milk, fresh thyme, and a bay leaf. Modern cooks often replace milk with beef stock, add flour for thickening, and top with Gruyère cheese and croutons, which were not part of the 1651 version.

It pairs nicely with a simple green salad dressed with vinaigrette, a slice of rustic country bread, or a classic roasted chicken (poulet rôti) that was common on French tables of the era.

The biggest pitfalls are burning the onions by cooking them too quickly, allowing the milk to scorch or curdle, and under‑seasoning the broth. Patience during caramelization and gentle simmering of the milk are key.

Milk provides a creamy, slightly sweet mouthfeel that coats the caramelized onions, resulting in a velvety texture. Broth would give a clearer, more savory profile, changing the soup’s character entirely.

Yes, you can caramelize the onions up to two days ahead and keep them refrigerated. Reheat the onions, add fresh milk, and simmer before serving. Store the finished soup in the fridge for up to three days; reheat gently on the stove.

The YouTube channel Tasting History with Max Miller specializes in recreating historic recipes from different eras, exploring the cultural context behind each dish, and presenting them with modern cooking techniques for home cooks.

Max Miller focuses on rigorous primary‑source research, often using original cookbooks and archival documents, and he emphasizes the story behind each recipe, whereas many other channels prioritize visual appeal over historical accuracy.