French Onion & Gruyère Stuffing

French Onion & Gruyère Stuffing brings the cozy flavor of French onion soup to a golden, buttery holiday side dish. Rustic sourdough cubes bake with sweet caramelized onions, savory herbs, and little pockets of melted Gruyère. The top turns beautifully crisp, while the center stays soft and tender.

The onions cook slowly in butter until they’re deep golden and naturally sweet. Then, a splash of broth and Worcestershire sauce adds savory depth without overpowering the bread. Fresh thyme gives the stuffing a lovely aroma, and Gruyère melts between the cubes for a rich, nutty finish.

This is a wonderful addition to Thanksgiving, Friendsgiving, or a cozy Sunday roast. Much of the prep can be done ahead, leaving more time for the rest of the holiday meal. Serve it warm from the baking dish, with those crisp golden edges ready for everyone to enjoy.

Recipe Yield: 8 servings

INGREDIENTS

12 cups day-old sourdough bread, cut into 3/4-inch cubes (about 1 lb)
1 1/2 cups freshly shredded Gruyère cheese, divided
3 large yellow onions, thinly sliced (about 2 lbs)
2 1/2 cups low-sodium chicken broth, divided, plus up to 1/4 cup more if needed
5 tbsp unsalted butter, divided
1 tbsp olive oil
3 garlic cloves, minced
1 tbsp Worcestershire sauce
2 large eggs
3/4 tsp kosher salt
1/2 tsp freshly ground black pepper
2 tbsp finely chopped fresh parsley
1 tsp finely chopped fresh rosemary
2 tsp fresh thyme leaves, plus a little extra for garnish

INSTRUCTIONS

1. Dry the bread:
Preheat the oven to 300°F. Spread the sourdough cubes on two baking sheets and bake for 20–25 minutes, stirring once, until dry and lightly crisp but not deeply browned. Set aside.

2. Caramelize the onions:
Melt 3 tbsp butter with the olive oil in a large skillet over medium heat. Add the sliced onions and 1/2 tsp kosher salt, then reduce the heat to medium-low. Cook for 40–55 minutes, stirring occasionally and more frequently toward the end, until deeply golden and soft.

3. Add the aromatics:
Stir in the garlic, thyme, rosemary, and Worcestershire sauce. Cook for 1 minute until fragrant.

4. Deglaze the skillet:
Pour in 1/4 cup chicken broth and stir, scraping up the browned bits. Cook for 1–2 minutes until most of the liquid has evaporated. Remove from the heat and let cool for 5 minutes.

5. Prepare the baking dish:
Preheat the oven to 375°F and lightly grease a 9×13-inch baking dish.

6. Prepare the broth mixture:
In a large bowl, whisk the eggs with the remaining 2 1/4 cups chicken broth, remaining 1/4 tsp kosher salt, and black pepper until evenly combined.

7. Combine the stuffing:
Add the dried sourdough cubes and caramelized onion mixture to the bowl. Fold gently until evenly moistened, then let stand for 5 minutes. If any cubes remain dry inside, add up to 1/4 cup more broth.

8. Add the Gruyère:
Fold in 1 cup shredded Gruyère and the chopped parsley, distributing the cheese and herbs throughout the bread.

9. Assemble the dish:
Transfer the stuffing to the prepared baking dish, spreading it evenly without pressing down firmly. Sprinkle the remaining 1/2 cup Gruyère over the top and dot with the remaining 2 tbsp butter.

10. Bake until golden:
Cover the dish with a lid or an inverted baking sheet and bake for 25 minutes. Uncover and bake for another 20–25 minutes, until the top is crisp and golden and the center reaches 165°F.

11. Rest and serve:
Let the stuffing rest for 10 minutes before serving. Sprinkle with a few fresh thyme leaves and serve warm.

Helpful Tips to Perfect This Recipe

• Dry the bread thoroughly: Day-old sourdough works beautifully, but oven-drying ensures the cubes absorb the savory broth without turning mushy. The bread should feel dry and firm before mixing.
• Give the onions enough time: Slow caramelization develops the deep, sweet flavor that makes this stuffing special. Stir more frequently toward the end, adding a small splash of water if the skillet gets too dark.
• Use freshly shredded Gruyère: Grating the cheese from a block helps it melt smoothly between the bread cubes. It adds rich, nutty flavor without making the stuffing overly heavy.
• Keep the center tender: The bread should be evenly moistened but not swimming in broth. Add a little extra broth if needed, then bake covered first to keep the center tender and uncover for crisp, golden edges.
• Prepare ahead for Thanksgiving: Dry the bread and caramelize the onions up to 2 days ahead, storing the onions refrigerated. Assemble the stuffing shortly before baking for the best texture. Refrigerate leftovers within 2 hours, use within 3–4 days, and reheat to 165°F.