About the Recipe
This slow cooker French onion soup is one of my favorite ways to turn simple ingredients into something deeply comforting. Long, gentle cooking coaxes sweetness from the onions while the broth develops rich, savory depth. Finished with melted cheese and served with crusty sourdough, it’s the kind of meal that feels cozy, classic, and a little bit special—without a lot of effort.
Ingredients
1/4 cup unsalted butter
6 thyme sprigs
1 bay leaf
5 pounds large sweet onions; vertically sliced (about 16 cups or 8 large onions)
1 tablespoon sugar
4 cups unsalted beef stock
2 cans been consommé
1/4 cup Worcestershire sauce
2 tablespoons red wine vinegar
1 1/2 teaspoons kosher salt
1 teaspoon black pepper
24 (1/2-ounce) slices Leaven Heaven sourdough baguette, toasted
5 ounces Gruyère cheese or Swiss/Gruyère cheese blend ; shredded (about 1 1/4 cups)
Preparation
Add the sliced onions, butter, olive oil, garlic, thyme, salt, and pepper to the slow cooker. Stir gently to coat the onions. Cover and cook on low for 8–10 hours or on high for 4–5 hours, stirring once or twice if possible, until the onions are deeply caramelized and golden.
Add the beef broth, beef consommé, bay leaf, and Worcestershire sauce if using. Stir, cover, and cook for an additional 30–60 minutes to allow the flavors to meld. Remove the bay leaf and adjust seasoning to taste.
Ladle the soup into oven-safe bowls, top each with a slice of toasted sourdough baguette, and finish with a generous handful of shredded cheese.
Broil until the cheese is melted and bubbly. Serve hot with extra baguette on the side.
Leaven Heaven Notes:
Russ would like to point out that the crocks in the photo are from his great grandmother and are his favorite bowls in our cabinets! It's important to save history when you have the opportunity. :-)