Onion Soup Fondue

This onion soup takes a different path than most French onion recipes. Five large onions sautéed in butter, simmered for 2 to 3 hours in beef broth, then refrigerated overnight so you can lift off the solidified fat before reheating. That overnight step gives you a cleaner, lighter broth with all the depth but none of the grease.

Monterey Jack cheese is the twist here instead of the usual Gruyere. Jack melts into soft, stretchy pools under the broiler without getting stringy or tough, and its mild flavor lets the onion broth be the star.

Thick-cut sourdough or French bread is a must. Thin slices disintegrate in the hot soup. One-inch slices toast up sturdy enough to float on top and hold the melted cheese without sinking.

Chef Tips

• Sauté the onions until transparent but NOT browned. This isn’t caramelized onion soup. You want sweet, soft onions that melt into the broth, not dark, caramelized ones.
• The overnight chill is not just for fat removal. The flavors deepen and meld during that rest, giving you a richer, more complex soup.
• Use ovenproof bowls or crocks under the broiler. Regular bowls can crack under the intense direct heat.
• Watch the cheese carefully under the broiler. You want it bubbly and soft, not browned. Jack cheese goes from melted to rubbery quickly if overcooked.

Variations

• Use Gruyere or Swiss cheese instead of Monterey Jack for a more traditional French onion soup profile.
• Add a splash of dry white wine or sherry to the broth during simmering for extra depth.
• Stir in a teaspoon of fresh thyme leaves before serving for an herbal note.