Slow Cooker French Onion Soup

French onion soup is flavorful and hearty. Simply prepare the soup in a lined slow cooker to warm and allow flavors to meld, and you’ll have a comforting and delicious French Onion Soup.

  • Prep Time

    15 minutes

  • Servings

    6 - 8

  • Cook Time

    6-8 hours (low); 3 hours (high)

  • Course

    Soups & Salads

You’ll Need...

Slow Cooker Liners



LINE your 5- to 6-quart slow cooker with a Reynolds® Slow Cooker Liner.

MELT butter in a large pot over medium heat. Add the onions, brown sugar, thyme and pepper and cook, stirring frequently, until the onions are very soft and caramelized, about 25 minutes.

ADD flour, stir to evenly coat onions.

Remove from heat and stir in soy sauce.

ADD caramelized onion mixture into slow cooker. Add the beef and chicken stocks, cover with lid, set slow cooker to high heat and cook for 3 hours, or until soup is hot.

REMOVE and discard thyme sprigs.

LADLE into bowls and top with cheese. Serve with sourdough bread (optional).