How To Make French Onion Soup

When I discovered that you can make caramelized onions in the slow cooker with no stirring and virtually no work, it was only a small step from there to French onion soup. Although I’ve made this bistro favorite the classic, Julia-inspired way, now that I know how to make it in the slow cooker, I’m probably never going back to stovetop!

Here’s a step-by-step recipe for blissfully delicious French onion soup made from start to finish in the slow cooker. Well, right up until the cheesy toast. You still need the oven for that, but with soup this easy, what’s a little broiling at the end?

Why the Slow Cooker Makes the Best French Onion Soup

This is one of those magical recipes that makes you say Oh, can it be so easy? And the answer to that, for once, is yes. Yes it can.

Here’s how it goes: Throw a few pounds of sliced onions in the slow cooker overnight, or for 12 hours (you can slice them in your food processor if you really want to hurry this along). Cook until dark and jammy; you don’t even need to stir. Pour in some broth and walk away again. Come back at dinnertime, ladle out soup, and broil with cheese and toast.

Perfect French onion soup, absolutely hands-off. This is why slow cookers exist, you guys.

For Your Information

This recipe calls for three pounds of yellow onions and 10 cups of beef broth. Sweet onions are marvelous here if you can get them. Feel free to use a combination of yellow and red onions, if needed.

The onions cook alone for 12 hours. Opt for cooking overnight if you plan to serve the soup for dinner the next day. After adding the broth and seasoning to the soup, cook agin for another six to eight hours. The total cook time for this recipe is about 20 hours in the slow cooker.

You will smell this soup cooking. But it smells delicious, so it’s OK!

INGREDIENTS

• 3 pounds yellow onions, peeled, sliced, and cut into quarter-moons
• 2 tablespoons unsalted butter, melted
• 2 tablespoons olive oil
• 2 teaspoons kosher salt, plus more as needed
• Freshly ground black pepper
• 10 cups reduced-sodium beef broth
• 2 tablespoons balsamic vinegar
• 3 tablespoons brandy (optional)
• To Serve
• 4 to 6 toasted baguette slices per bowl
• 1/3 cup grated Gruyère cheese per bowl (1 1/3 to 2 cups total)
• Chopped shallot or fresh onion (optional)

EQUIPMENT

• Cutting board and chef's knife
• 5-quart or larger slow cooker
• Wooden spoon
• Oven-safe soup bowls
• Rimmed baking sheet

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