Ingredients

For the Soup:

• 3 pounds yellow onions (about 4 large or 6 medium)
• 6 tablespoons unsalted butter, divided
• 1 teaspoon dried thyme
• 2 dried bay leaves
• 2 1/2 teaspoons kosher salt, divided (plus more as needed)
• 1/2 teaspoon freshly ground black pepper
• 3 medium carrots
• 3 medium celery stalks
• 3 cloves garlic
• 2 pounds boneless, skinless chicken breasts or thighs
• ¾ cup low-sodium chicken broth
• 1/4 cup all-purpose flour
• 6 cups low-sodium chicken broth

For the Cheesy Toasts (Optional):

• 1/2 baguette
• 2 ounces Gruyère cheese (about heaping 1/2 cup)

Instructions

Make the Soup:

1. Prepare the Onions: Peel, halve, and thinly slice the onions (about 10 cups).
2. Caramelize the Onions: Melt 4 tablespoons of butter in a large Dutch oven or heavy-bottomed pot over medium heat. Add the onions, thyme, bay leaves, 1 1/2 teaspoons salt, and black pepper. Cook, stirring often, until the onions become soft and deep golden brown, about 35-45 minutes.
3. Prepare the Vegetables: While onions cook, peel and slice the carrots into 1/4-inch rounds (about 1 1/4 cups). Slice celery into 1/4-inch pieces (about 1 cup). Mince the garlic.
4. Cook the Vegetables: Add the remaining 2 tablespoons of butter to the pot. Stir in the carrots, celery, and garlic. Cook for about 5 minutes until the vegetables are slightly tender.
5. Prepare the Chicken: Season the chicken with the remaining 1 teaspoon of salt. If using thick chicken breasts, butterfly them by slicing them in half lengthwise for even cooking.
6. Deglaze the Pot: Pour in ¾ cup chicken broth, scraping the bottom of the pot to loosen any browned bits. Cook for 2-3 minutes until mostly evaporated.
7. Thicken the Soup: Sprinkle the flour over the mixture and stir constantly for 1 minute to cook off the raw flour taste.
8. Simmer the Soup: While stirring, pour in the chicken broth. Add the chicken in a single layer and bring the mixture to a lively simmer over medium-high heat.
9. Cook the Chicken: Reduce the heat to maintain a gentle simmer. Let cook, stirring occasionally, until the chicken is cooked through (165°F internal temperature). This takes about 10 minutes for thighs or 12-20 minutes for breasts.

Make the Cheesy Toasts (Optional):

1. Preheat Broiler: Position an oven rack 3-4 inches from the broiler and set the oven to broil.
2. Slice the Bread: Cut the baguette into 1-inch-thick slices and place them on a baking sheet.
3. Add the Cheese: Grate the Gruyère cheese and evenly sprinkle it over the bread slices.
4. Broil the Toasts: Broil for 30 seconds to 1 minute until the cheese is melted and bubbly.

Final Steps:

1. Shred the Chicken: Remove the chicken from the pot and shred it using two forks. Return the shredded chicken to the soup. Discard the bay leaves. Taste and adjust seasoning if needed.
2. Serve: Ladle the soup into bowls and top each with a cheesy toast.

Storage Tips:

• Refrigerate leftovers in an airtight container for up to 4 days.
• Freeze for up to 3 months.

Nutrition