Cooks' Illustrated Onion Soup Recipe

Name: Cooks' Illustrated Onion Soup
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Yield: 4 servings
Ingredients: 3 tablespoons unsalted butter , cut into 3 pieces; 6 large yellow onions (about 4 pounds), halved and cut pole to pole into 1/4-inch-thick slices (see illustration below); Table salt; 2 cups water , plus extra for deglazing; 1/2 cup dry sherry; 4 cups low-sodium chicken broth (see note); 2 cups beef broth (see note); 6 sprigs fresh thyme , tied with kitchen twine; 1 bay leaf; Ground black pepper; Cheese Croutons; 1 small baguette , cut into 1/2-inch slices; 8 ounces shredded Gruyere cheese (about 2 1/2 cups)

Servings: persons

3 tablespoons unsalted butter , cut into 3 pieces
6 large yellow onions (about 4 pounds), halved and cut pole to pole into 1/4-inch-thick slices (see illustration below)
Table salt
2 cups water , plus extra for deglazing
1/2 cup dry sherry
4 cups low-sodium chicken broth (see note)
2 cups beef broth (see note)
6 sprigs fresh thyme , tied with kitchen twine
1 bay leaf
Ground black pepper
Cheese Croutons
1 small baguette , cut into 1/2-inch slices
8 ounces shredded Gruyere cheese (about 2 1/2 cups)

1
1. For the soup: Adjust oven rack to lower-middle position and heat oven to 400 degrees. Generously spray inside of heavy-bottomed large (at least 7-quart) Dutch oven with nonstick cooking spray. Place butter in pot and add onions and 1 teaspoon salt. Cook, covered, 1 hour (onions will be moist and slightly reduced in volume). Remove pot from oven and stir onions, scraping bottom and sides of pot. Return pot to oven with lid slightly ajar and continue to cook until onions are very soft and golden brown, 1 1/2 to 1 3/4 hours longer,
2
2. Place pot over medium-high heat. Cook onions, stirring frequently and scraping bottom and sides of pot, until liquid evaporates and onions brown, 15 to 20 minutes. Continue to cook, stirring frequently, until pot bottom is coated with dark crust, 6 to 8 minutes, adjusting heat as necessary. Stir in 1/4 cup water, scraping pot bottom and cook until water evaporates and pot bottom has formed another dark crust, 6 to 8 minutes. Repeat process 2 or 3 x, until onions are very dark brown. Stir in sherry and cook until sherry evaporates, about 5 minutes.
3
3. Stir in broths, 2 cups water, thyme, bay leaf, and 1/2 teaspoon salt, scraping up any final bits of browned crust on bottom and sides of pot. Increase heat to high and bring to simmer. Reduce heat to low, cover, and simmer 30 minutes. Remove and discard herbs, then season with salt and pepper.
4
4. For the croutons: arrange baguette slices on baking sheet and bake in 400-degree oven until bread is dry, crisp, and golden at edges, about 10 minutes. Set aside.
5
5. To serve: Adjust oven rack 6 inches from broiler element and heat broiler. Set individual broiler-safe crocks on baking sheet and fill each with about 1 3/4 cups soup. Top each bowl with 1 or 2 baguette slices (do not overlap slices) and sprinkle evenly with Gruyere. Broil until cheese is melted and bubbly around edges, 3 to 5 minutes. Let cool 5 minutes before serving.

774

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.

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

My Personal Notes

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How did you like this recipe?

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

You need 13 ingredients. The key ingredients include: 3 tablespoons unsalted butter , cut into 3 pieces, 6 large yellow onions (about 4 pounds), halved and cut pole to pole into 1/4-inch-thick slices (see illustration below), Table salt, 2 cups water , plus extra for deglazing, and more.

Yes, Cooks' Illustrated 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!

Cooks' Illustrated Onion Soup

Tips for the best results

Variations & substitutions

My Personal Notes

How did you like this recipe?

Frequently Asked Questions