Soup Recipes Vegetable Soup Recipes Onion Soup Recipes French Onion Soup Recipes Slow Cooker French Onion Soup 4.8 (407) 317 Reviews 48 Photos This slow cooker French onion soup is ridiculously easy to make, mainly since it cooks in a slow cooker! After you caramelize the onions, it simmers all day, and you come home to an amazing aroma and a fabulous meal for a cold winter day. Using a blend of cheeses on top of the bread makes this soup extra rich and delicious. Submitted by Chandrav Updated on September 9, 2024 Tested by Allrecipes Test Kitchen Tested by Allrecipes Test Kitchen The Allrecipes Test Kitchen staff are a team of culinary pros who make and vet recipes using only equipment you'd find in a home kitchen. Staff credentials vary but include training at the Culinary Institute of America; kitchen stints in fine dining restaurants; and countless hours in the test kitchen itself. Meet the Allrecipes Test Kitchen Save Rate Print Share Add Photo 48 48 48 48 Prep Time: 30 mins Cook Time: 4 hrs 45 mins Total Time: 5 hrs 15 mins Servings: 8 Jump to Nutrition Facts Cook Mode (Keep screen awake) Ingredients 1x 2x 4x Oops! Something went wrong. Our team is working on it. Original recipe (1X) yields 8 servings 6 tablespoons butter 4 large yellow onions, sliced and separated into rings 1 tablespoon white sugar 2 cloves garlic, minced ½ cup cooking sherry 7 cups reduced-sodium beef broth 1 teaspoon sea salt, or to taste ¼ teaspoon dried thyme 1 bay leaf 8 slices of French bread ½ cup shredded Gruyere cheese ⅓ cup shredded Emmental cheese ¼ cup freshly shredded Parmesan cheese 2 tablespoons shredded mozzarella cheese Directions Gather all ingredients. Dotdash Meredith Food Studios Heat butter in a large, heavy pot over medium-high heat. Add onions; cook and stir until translucent, about 10 minutes. Dotdash Meredith Food Studios Sprinkle onions with sugar; reduce heat to medium. Cook, stirring constantly, until onions are soft and caramelized, at least 30 minutes. Stir in garlic and cook until fragrant, about 1 minute. Dotdash Meredith Food Studios Stir sherry into onion mixture; scrape the bottom to dissolve the small bits of browned food. Dotdash Meredith Food Studios Transfer onions into a slow cooker and pour in beef broth. Season with sea salt; stir in thyme and bay leaf. Dotdash Meredith Food Studios Cover and cook on Low for 8 to 10 hours or on High for 4 to 6 hours. Dotdash Meredith Food Studios Preheat the oven broiler about 10 minutes before serving. Set an oven rack about 8 inches from the heat source. Arrange bread slices on a baking sheet; broil until toasted, 1 to 2 minutes per side. Dotdash Meredith Food Studios Lightly toss Gruyere, Emmental, Parmesan, and mozzarella cheeses in a bowl. Dotdash Meredith Food Studios Fill oven-safe soup crocks 3/4 full with onion soup and float a bread slice in each bowl. Dotdash Meredith Food Studios Top each with about 2 tablespoons cheese mixture. Dotdash Meredith Food Studios Place filled bowls onto a baking sheet and broil until cheese topping is lightly browned and bubbling, about 2 minutes. Dotdash Meredith Food Studios Cook’s Note You do not have to caramelize the onions; you can melt the butter in your crockpot, stir in the onions to coat, add the remaining ingredients, and cook. However, caramelizing the onions makes for a much, much better soup!If you like, put all the soup components — soup, toasted bread, and cheese mixture — out on the table and let people make their soup! This seems to be the favored method when I host a craft night. People can make their own decisions about what they want in or on their soup! I Made It Print 1,399 home cooks made it! Nutrition Facts (per serving) 442 Calories 16g Fat 57g Carbs 18g Protein Show Full Nutrition Label Hide Full Nutrition Label Nutrition Facts Servings Per Recipe 8 Calories 442 % Daily Value * Total Fat 16g 21% Saturated Fat 9g 45% Cholesterol 38mg 13% Sodium 1539mg 67% Total Carbohydrate 57g 21% Dietary Fiber 3g 10% Total Sugars 10g Protein 18g 35% Vitamin C 4mg 4% Calcium 222mg 17% Iron 4mg 22% Potassium 283mg 6% * Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs. ** Nutrient information is not available for all ingredients. Amount is based on available nutrient data. (-) Information is not currently available for this nutrient. If you are following a medically restrictive diet, please consult your doctor or registered dietitian before preparing this recipe for personal consumption.