Slow Cooker French Onion Soup Recipe

Name: Slow Cooker French Onion Soup
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Yield: 4 servings
Ingredients: 1/4 cup unsalted butter; 6 thyme sprigs; 1 bay leaf; 5 pounds large sweet onions, vertically sliced (about 16 cups); 1 tablespoon sugar; 6 cups unsalted beef stock (such as Swanson); 2 tablespoons red wine vinegar; 1 1/2 teaspoons kosher salt; 1 teaspoon black pepper; 24 (1/2-ounce) slices whole-grain French bread baguette; 5 ounces Gruyere cheese, shredded (about 1 1/4 cups)

Servings: persons

1/4 cup unsalted butter
6 thyme sprigs
1 bay leaf
5 pounds large sweet onions, vertically sliced (about 16 cups)
1 tablespoon sugar
6 cups unsalted beef stock (such as Swanson)
2 tablespoons red wine vinegar
1 1/2 teaspoons kosher salt
1 teaspoon black pepper
24 (1/2-ounce) slices whole-grain French bread baguette
5 ounces Gruyere cheese, shredded (about 1 1/4 cups)

1
Place butter, thyme, and bay leaf in the bottom of a 6-quart electric slow cooker. Add onions; sprinkle with sugar. Cover and cook on HIGH for 8 hours.
2
Remove thyme and bay leaf; discard. Add stock, vinegar, salt, and pepper; cook, covered, on HIGH for 30 minutes.
3
Preheat broiler to high.
4
Arrange bread in a single layer on 2 baking sheets; broil 30 seconds on each side or until toasted. Place 1 cup soup in each of 12 (8-ounce) ramekins or ovenproof bowls, or follow freezing instructions. Top each serving with 2 bread slices and about 2 tablespoons cheese. Place 6 ramekins on a jelly-roll pan; broil 2 minutes or until cheese melts and begins to brown. Repeat procedure with remaining 6 ramekins, bread slices, and cheese.

660

kcal

Calories

Fat

Carbs

Protein

Fat Carbs Protein

* Per serving · 4 servings · Values may vary.

Tips for the best results

Read through all the steps once before you start and measure out your ingredients first — it makes everything go more smoothly.
Taste as you go and adjust the seasoning before serving.
Avoid overcrowding the pan — cook in batches if needed for the best texture.
Let the dish rest for a few minutes before serving so the flavors settle.
Store leftovers in an airtight container in the fridge and enjoy within a few days.

Variations & substitutions

Use a neutral oil or a plant-based spread in place of butter for a dairy-free version.
Brown sugar instead of white sugar adds a deeper, more caramel-like flavor.

No specific allergen information. Please check the ingredient list for possible allergens.

My Personal Notes

Saved locally in your browser — visible only to you.

How did you like this recipe?

This recipe makes 4 servings. You can adjust the portion size directly on this page.

You need 11 ingredients. The key ingredients include: 1/4 cup unsalted butter, 6 thyme sprigs, 1 bay leaf, 5 pounds large sweet onions, vertically sliced (about 16 cups), and more.

Yes, Slow Cooker French Onion Soup falls under the Soups & Stews category and is a great choice for this type of meal.

Store leftovers in an airtight container in the refrigerator for up to 3–4 days. Reheat gently before serving.

That's it — enjoy your meal!

Slow Cooker French Onion Soup

Tips for the best results

Variations & substitutions

My Personal Notes

How did you like this recipe?

Frequently Asked Questions