Slow Cooker French Onion Pot Roast Soup

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The second the temperature drops below 50 degrees, and the sweaters come off the hangers, we’re officially entering soup season. And one of the first soups on our list is this French Onion Pot Roast soup. It’s the kind of cozy, slow-cooked dinner that makes cooking at home sound like the best plan of the week. 

This Slow Cooker French Onion Pot Roast recipe will cure your craving for an incredibly cozy, soul-warming meal. This recipe takes everything you love about a French onion soup and gives it a hearty twist with the addition of chuck roast and fresh herbs. As it cooks, it becomes so tender and basically falls apart. It’s melt-in-your-mouth good! The caramelized, sweet onions cook in a herby, savory broth that is infused with bourbon, fresh thyme, rosemary, and Worcestershire sauce. As everything simmers for about 10 hours, everything becomes caramelized, tender, and full of flavor. 

And no French onion soup is finished without toasted bread (or croissants) with melty gruyere cheese. It adds a nutty finish, and the crisp, toasted bread is delicious for dipping in the sauce to soak up all the goodness!

The best part about this dish is that the slow cooker does most of the work! Make a big pot and let it set overnight or while you’re at work so that you have a delicious dinner ready to go whenever you get home. It’s the perfect prescription for a cold day – easy, warm, and delicious!

Why You’ll Love This French Onion Pot Roast Soup

• The slow cooker does most of the work! All you have to do is throw the ingredients in the slow cooker pot and let time work its magic. Once the meat is tender, you’re ready to shred it and enjoy.
• Short ingredient list! We love a recipe that doesn’t have a whole laundry list of ingredients. You may even have most of these ingredients in your pantry and fridge. 
• The perfect soup for a chilly day! It’s warm, rich, and perfect to serve on a cold day alongside a warm croissant or a slice of cheesy bread.

How to Make This Slow Cooker French Onion Pot Roast Soup

Step 1. Slice onions and measure ingredients.

Creating a mise en place (or set up) of ingredients will make this process super smooth and easy. That way, you don’t forget to add everything. 

Start by thinly slicing several yellow onions, using a sharp knife and a wooden cutting board. Measure out all your mix-ins- butter, broth, brown sugar, Worcestershire sauce, and seasonings. 

Once you have everything measured and the counter in front of you, you’re ready to add them to the slow cooker pot.

Step 2. Add soup ingredients to the slow cooker pot and cook on low for 8-10 hours.

Start by adding the sliced onions and minced garlic to the bottom of the slow cooker pot. Melt butter and toss the onions in the melted butter. Mix in flour, brown sugar, and bourbon. The bourbon is optional but adds a sweet, smoky flavor to the broth.

Place the chuck roast on top of the onions and pour 1 cup of broth on the sides of the roast. Season the top of the meat with some salt, fresh thyme, and rosemary. Add a couple of bay leaves to the pot before closing the lid. 

Turn the slow cooker on low heat and let it cook for 8-10 hours. Check the roast at 8 hours to see if the meat is tender. The onions should be a golden brown color, and the meat should be tender that it falls apart easily when you shred it with a fork. If you feel it needs 1-2 more hours of cooking, it won’t hurt to cook it for longer. 

Tip: If you are on the hunt for an amazing slow cooker that does it all, check out the GreenPan 14-in-One Slow Cooker. We meal prep at least 2-3 meals each week in our GreenPan. It not only slow cooks soups; it bakes, makes rice, simmers, sautés, and so much more. We’re still discovering things that we can do with ours. And the best part is that it is nonstick, super easy to clean, and free of PFA’s. It’s also super lightweight and super portable!

Step 3. Shred the meat, add more broth, increase heat to high, and cook for 20 more minutes.

Once the meat is tender and falls apart, transfer it to a plate and use a couple of forks to shred the meat and remove any excess fat. Add the rest of the broth to the pot and give the soup a good stir.

Place the lid back on the pot and turn the heat up to high for about 15 minutes to simmer. This will help the flavors of the soup deepen in the broth. 

Step 4. Toast cheesy bread in the oven to serve alongside the soup.

As the soup heats up in the pot, preheat the oven to toast some bread. We used croissants, but you can toast some cheesy baguette slices if that’s more of your vibe. Either works and tastes delicious with this soup. 

Once the oven reaches a temperature of 375°F, line a sheet pan with croissant or bread slices, sprinkle the tops with cheese, and let them toast for about 5 minutes until the cheese is melty. As the bread cooks, it will get crispy, and the cheese will get gooey and so delicious.

Ladle several spoonfuls of soup into a bowl and serve with the crispy bread. Sprinkle some extra gruyere cheese, season with some salt and black pepper, and enjoy!

Tips for Making Crockpot French Onion Pot Roast Soup

• Slice onions thinly and evenly. This helps them soften and break down as they cook to create that classic caramelized French onion soup flavor. Keeping them uniform in size will also help them cook evenly.
• Give the onions plenty of time to cook. You start by cooking the onions on low in a small amount of broth. This will allow the onions to caramelize and soften while the beef also becomes tender. They will cook for about 8 hours, but if you need longer, keep them in there for 9-10 hours on low heat to develop so much flavor.
• Shred the beef before adding the remaining broth. Once the chuck roast is fall-apart-tender, remove any pieces of fat and shred the meat into bite-sized pieces. Stir it back into the pot and add the remaining broth to cook for a final time. This will give the beef time to soak up all those yummy flavors in the broth.
• Serve with cheesy Gruyère bread. Toast cheesy croissants or baguette slices and serve with the soup. The melty Gruyère and crisp bread is a delicious pairing with this soup.

Storing and reheating leftover French onion soup

Store leftovers in an airtight container in the refrigerator for up to 3-4 days. Reheat on the stovetop over medium heat or in the microwave. You can also return it to your slow cooker to reheat. 

Some slow cookers, like the GreenPan Slow Cooker we use, have a reheat option that reheats the soup evenly to perfection!

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