slow cooker french onion soup

Get the classic savory flavors of French Onion Soup with minimal effort thanks to this slow-cooker version! Just top it with bread and cheese and melt it all under the broiler when ready to serve!

How many soup recipes can I post on this blog?! Um. Unfortunately for you {or fortunately, if you're a soup person}, the limit does not exist. This year's inaugural recipe to soup season is this incredible Slow Cooker French Onion Soup! Maximum deliciousness and minimal effort is what I'm all about. This recipe combines the classic savory, satisfying flavors of caramelized onions with a super easy, hands off approach. It's not quite set-it-and-forget-it, but close enough. You're gonna love it!

While I thought this was pretty spectacular as I made it, my only advice to you is to cook the onions even longer! Believe it or not, even with a solid 4-5 hrs in the slow cooker, the onions were still a tiny bit crunchy. So I would say, make the onions with the butter, oil, seasonings, flour, all the stuff, dump them in the crockpot, and let them cook for at least a few hours before adding the broth. I've even seen some recipes let the onions cook overnight on low! Depends how committed you are. Again, I thought this "quicker" slow cooked version was still totally delicious.

The best part of french onion soup, as anyone knows, is the ooey, gooey, cheesy bread on top! My household normally runs on chewy, crusty pugliese bread, but we all agree that the best kind of bread for this is -duh- french bread. Just buy the big chubby $1 baguette at your local grocery store, that's the one that works best! As for cheese, my family is a little wimpy when it comes to strong cheeses so we usually go for mozzarella, provolone, and parmesan. #italians. Gruyere is the tradition, so if you're a little more adventurous, go for it!

This slow cooker french onion soup is seriously delicious and SO simple to make! I hope you enjoy it sometime this soup season! Happy cooking! 🙂

Looking for more soup recipes? Check out my Creamy Tomato Basil Soup, Green Pea Soup with Crispy Prosciutto, Corn Chowder with Bacon and Shrimp, or my Creamy Poblano Pepper Soup!

Print Recipe

5 from 1 vote

slow cooker french onion soup

Prep Time30 minutes mins

Cook Time10 hours hrs

Total Time10 hours hrs 30 minutes mins

Servings: 5

Author: Valentina | The Baking Fairy

Ingredients

• 1 ½ lbs sweet yellow onions sliced thinly
• 6 tablespoon butter
• 4 tablespoon olive oil
• 3 tablespoon flour
• 3 tablespoon water
• ½ cup white wine
• 2 teaspoon sugar
• 1 teaspoon salt
• ½ teaspoon pepper
• ½ teaspoon thyme
• 4 cups beef broth use veggie broth for a vegetarian version!
• 5 thick slices French bread
• 5 slices provolone cheese
• 1 cup shredded mozzarella cheese
• ½ cup freshly grated Parmesan cheese

Instructions

• In your crockpot set on high, combine butter, oil, onions, sugar, salt, pepper, and thyme.
• In a small cup, whisk together the flour and water until smooth, and pour into the slow cooker.
• Finally, add in the wine, cover, and let the onions cook for about 3-4 hrs on high (8-10 hrs on low), until onions are very soft and golden brown.
• When almost ready to serve, add in the beef or veggie broth, and allow soup to cook for at least 1 more hour.
• When ready to serve, pour the soup into 5 oven-safe bowls or ramekins. Top each bowl with a slice of bread, and put one slice of provolone on top of each. Sprinkle the mozzarella and parmesan on top.
• Place bowls under the broiler (around 450-500F) for 2-3 minutes, watching VERY carefully, until cheese is melted and bubbly. Serve immediately!