crock pot french onion soup with Crispy Bacon

You catch the smell through the steam vent and suddenly you are starving. The sweet richness of caramelized onions fills the air. You sense something warm and full of flavor coming from your kitchen.

It9s that deep onion smell, the one that sticks to your heart and makes you remember cozy nights and comfort food. You recall the slow simmer, the way the onions get soft and golden like little jewels melting in olive oil.

And then you spot that float valve gently rising and the faint hiss of the valve tells you your soup is ready. The broth depth is rich. You remember why you love making this slow cooker French onion soup. It warms you up from inside out.

The Truth About Fast Tender Results

• The slow cooker does the trick by caramelizing onions perfectly over hours without your constant watch.
• You don9t gotta stir every 5 minutes but occasional stirring helps those onions brown evenly.
• Using a natural release keeps soup flavors sealed and helps broth deepen as it rests.
• The float valve will hiss to tell you when pressure9s built just right for that perfect texture.
• This method saves your burner space and energy while delivering dreamy tender onions and broth.

Everything You Need Lined Up

• 12 small to medium yellow onions peeled and thinly sliced
• 3 medium red onions peeled and thinly sliced for extra sweetness
• 6 tablespoons olive oil to help with caramelizing and richness
• ½ teaspoon kosher salt and ½ teaspoon dried thyme for seasoning
• 1 ½ cups beef broth and 1 ½ cups chicken broth for balanced broth depth
• Kosher salt and black pepper to taste, gotta season well at the end
• 6-8 slices of thick French bread to toast and float on top
• Swiss cheese either thin slices or grated, whatever you got on hand

The Exact Process From Start to Finish

1. Peel and thinly slice all your onions. This part takes a lil time but it9s worth it.
2. Dump the sliced onions, olive oil, kosher salt, and dried thyme into your slow cooker. Stir it all real good to mix flavors.
3. Cover and set your cooker on low for 10 to 12 hours. Don9t forget to stir occasionally if you remember, that helps caramelize evenly.
4. When onions are deep golden and caramelized, pour in the beef and chicken broth. Stir gently to combine that broth depth.
5. Cover again, but now crank the cooker on high for 2 to 3 hours. Let the soup heat through and those flavors get close and cozy.
6. Season the soup with more kosher salt and black pepper to your liking. Taste is key here.
7. While soup simmers, preheat your broiler to toast the bread. Drizzle olive oil lightly on slices and broil each side for 1 to 2 minutes until golden and crisp.
8. Ladle the hot soup into oven-safe bowls. Top each with a slice of that toasted bread and sprinkle on some Swiss cheese.
9. Pop bowls under the broiler until the cheese melts and bubbles nicely. Serve it up piping hot.

Valve Hacks You Need to Know

• If you gotta step away, try slow release or natural release to avoid splatter and keep that broth depth perfect.
• When you hear the valve hiss, that9s the signal your soup is under pressure and cooking right.
• If pressure sticks, use a little cold water trick near the valve to help it release faster safely.
• Make sure float valve moves freely before cooking, that way you get consistent pressure and perfect onions.

What It Tastes Like Fresh From the Pot

This soup tastes like a warm hug on a chilly day. The sweetness from caramelized onions blends with savory broth for rich comfort.

It9s kinda sweet and nutty, with earthy thyme lingering just enough to make every bite interesting but never overwhelming.

The toasted bread soaks up some broth while staying firm enough to hold the melty Swiss cheese you draped on top.

When the cheese bubbles and browns a little under the broiler, it adds a cozy creaminess that brings the whole bowl together.

How to Store This for Later

• Keep leftover soup in airtight containers in the fridge up to 4 days. Reheat slowly so onions keep tender and flavor stays rich.
• If you want to freeze, ladle soup into freezer-safe containers but leave out the bread and cheese till serving day.
• Freeze up to 3 months and thaw in the fridge overnight before reheating gently on the stove or pressure cooker.

Your Most Asked Questions Answered

• Can I use other onions? You bet! Yellow and red onions give great flavor but sweet or white onions work too.
• Do I have to stir the onions a lot? Nah, just stir occasionally during the long slow cook to help even caramelizing.
• Can I skip the broiler step? Sure, it9s awesome for melted cheese but soup is still tasty without it.
• Why is my soup not as deep in flavor? Might be broth quality or not enough caramelization on onions. Slow cooking low and long really builds broth depth.
• What if my float valve won9t move? Check if anything stuck it and gently wiggle. Never force it to avoid damage.
• Can I make this pressure cooker style? Totally, but I recommend slow cooking with occasional stirring for best caramelization results.

For related recipes using pressure cookers and rich broth depth, check out our cottage cheese queso dip with Raisins and Dates and tuna steak recipes with Ground Beef. These recipes also showcase a great balance of flavors and cooking techniques.

Slow-Cooker Caramelized Onions & French Onion Soup | Make Ahead Mondays

This slow-cooker French onion soup brings deep, rich flavor from caramelized onions, hearty broth, and toasted cheesy croutons. Perfect for make-ahead comfort.

Print Recipe Pin Recipe

Prep Time 10 minutes mins

Cook Time 11 hours hrs

Total Time 11 hours hrs 10 minutes mins

Servings 6 people

Calories 497 kcal

Equipment

• 1 Slow cooker
• 1 Broiler
• 1 Knife for slicing onions

Ingredients

  

Main Ingredients

• 12 Yellow onions small to medium, peeled and thinly sliced
• 3 Red onions medium, peeled and thinly sliced
• 6 tablespoons Olive oil divided, for caramelizing and drizzling
• ½ teaspoon Kosher salt for seasoning
• ½ teaspoon Dried thyme for seasoning
• 1.5 cups Beef broth
• 1.5 cups Chicken broth
• Kosher salt and black pepper to taste
• 6-8 slices French bread 1 to 1.5-inches thick each
• Olive oil for drizzling on bread
• 6-8 slices Swiss cheese thinly sliced or ¼ pound grated

Instructions

 

Instructions

• Peel and thinly slice all your onions.
• Dump the sliced onions, olive oil, kosher salt, and dried thyme into your slow cooker. Stir it all real good to mix flavors.
• Cover and set your cooker on low for 10 to 12 hours. Stir occasionally for even caramelizing.
• When onions are deep golden and caramelized, pour in the beef and chicken broth. Stir gently to combine.
• Cover again and set the cooker on high for 2 to 3 hours to heat through.
• Season the soup with more kosher salt and black pepper to taste.
• While soup simmers, preheat your broiler. Drizzle olive oil lightly on bread slices and toast under broiler 1–2 minutes per side until golden.
• Ladle hot soup into oven-safe bowls. Top each with a slice of toasted bread and Swiss cheese.
• Place bowls under broiler until cheese is melted and bubbly. Serve hot.
• Store leftovers in airtight containers in fridge up to 4 days or freeze without bread and cheese up to 3 months.

Notes

For best results, use both beef and chicken broth and allow plenty of time for onions to fully caramelize. Toasted bread and melty cheese add incredible flavor and texture.