3 ratings

Slow-cooker Onion Soup With Crusty Toast

French onion soup in a slow cooker
Slow-cooker Onion Soup With Crusty Toast
LauriPatterson/E+ via Getty Images

A simple way to prepare this cheesy and delicious soup. This soup recipe calls for you to use a slow cooker to handle the job of cooking. Let the flavors of the onions simmer in the broth as it cooks. Serve a sprinkle of cheese and toasted French bread.

Ready in
6 h 25 m
25 m
(prepare time)
6 h
(cook time)
Calories Per Serving


The onions in step 1 can be cooked up to 2 days in advance. If desired, add shredded cooked beef or chicken along with the broth and skip the cheese garnish.


  • 3 jumbo yellow onions, peeled, halved, cut into thin wedges
  • 1 Tablespoon butter
  • 1 Tablespoon vegetable oil
  • 1 1/2 Tablespoon flour
  • 6 Cups all-purpose slow-cooker broth or equal parts chicken and beef broth
  • 2-3 Tablespoons dry sherry or cognac, optional
  • 2 Teaspoons salt
  • 6 thick slices crusty French bread
  • 1 1/2 Cup loosely packed shredded cheese, such as Gruyere


Step 1: Put 3 onions in the slow cooker; set on high. Stir in 1 tablespoon butter and 1 tablespoon oil. Slow-cook on high, stirring occasionally, until deeply browned, 5-6 hours. (Or cook the onions in a Dutch oven over lowest heat, stirring often, about 2 hours. Watch carefully so they do not burn.)

Step 2: Stir in 1 1/2 tablespoons flour; cook 1 minute. Add 6 cups broth, 2-3 tablespoons sherry and 2 teaspoons salt. Adjust seasonings. Slow-cook (or simmer in the pot) 1 hour.

Step 3: Heat oven to 450F. Toast 6 bread slices on a baking sheet in the oven until crusty, 3-4 minutes. Ladle the soup into ovenproof bowls. Top with the toasted bread; sprinkle with 1 1/2 cups cheese. Bake until cheese is melted, about 5 minutes.