Creamy Swiss Chard & Gruyère Gratin with Garlic Herb Crust

🌍 Cuisine: French
🏷️ Category: Side Dish
⏱️ Prep: 25 minutes
🍳 Cook: 40 minutes
👥 Serves: 6 servings

📝 About This Recipe

This elegant gratin elevates humble Swiss chard into a luxurious side dish that rivals any classic potato preparation. By utilizing both the earthy, vibrant leaves and the crunchy, celery-like stalks, we create a complex texture profile bathed in a silky, nutmeg-scented Mornay sauce. Topped with a golden, buttery shroud of Gruyère and sourdough crumbs, it is the ultimate comfort food for a sophisticated dinner party or a cozy Sunday roast.

🥗 Ingredients

The Chard Base

  • 2 large bunches Swiss Chard (approx. 1.5 lbs, cleaned and stems separated from leaves)
  • 1 tablespoon Unsalted Butter (for sautéing)
  • 2 pieces Shallots (finely minced)
  • 3 cloves Garlic (minced)

The Mornay Sauce

  • 3 tablespoons Unsalted Butter (at room temperature)
  • 3 tablespoons All-purpose Flour
  • 2 cups Whole Milk (warmed slightly)
  • 1/4 cup Heavy Cream (for extra richness)
  • 1 cup Gruyère Cheese (freshly grated)
  • 1/4 teaspoon Nutmeg (freshly grated)
  • 1/2 teaspoon Kosher Salt (plus more to taste)
  • 1/4 teaspoon Black Pepper (freshly cracked)

The Gratin Topping

  • 3/4 cup Sourdough Breadcrumbs (coarsely ground)
  • 1/4 cup Parmesan Cheese (freshly grated)
  • 1 teaspoon Fresh Thyme (leaves only, chopped)
  • 2 tablespoons Melted Butter

👨‍🍳 Instructions

  1. 1

    Preheat your oven to 400°F (200°C) and lightly grease a 1.5 to 2-quart baking dish with butter.

  2. 2

    Prepare the chard: Strip the leaves away from the center stalks. Chop the stalks into 1/2-inch pieces and roughly chop the leaves into 2-inch ribbons. Keep them in separate piles.

  3. 3

    Bring a large pot of salted water to a boil. Blanch the chopped chard stalks for 3-4 minutes until tender-crisp. Add the leaves to the same pot and blanch for 1 minute more until wilted.

  4. 4

    Drain the chard into a colander and immediately rinse with cold water to stop the cooking. Once cool, use your hands or a clean kitchen towel to squeeze as much liquid out as possible. This prevents a watery gratin.

  5. 5

    In a large skillet over medium heat, melt 1 tablespoon of butter. Sauté the minced shallots and garlic for 2-3 minutes until soft and fragrant, then stir in the squeezed chard to coat. Remove from heat.

  6. 6

    To make the roux, melt 3 tablespoons of butter in a medium saucepan over medium heat. Whisk in the flour and cook for 2 minutes, stirring constantly, to remove the raw flour taste (do not let it brown).

  7. 7

    Slowly pour in the warmed milk and heavy cream while whisking vigorously to prevent lumps. Continue cooking and stirring until the sauce thickens enough to coat the back of a spoon (about 5-7 minutes).

  8. 8

    Remove the sauce from heat. Stir in 3/4 cup of the Gruyère cheese, nutmeg, salt, and pepper until the cheese is melted and the sauce is glossy.

  9. 9

    In a small bowl, toss together the sourdough breadcrumbs, Parmesan, thyme, and melted butter until well combined.

  10. 10

    Combine the sautéed chard mixture with the Mornay sauce in the skillet or a mixing bowl, stirring until the greens are evenly enveloped in cream.

  11. 11

    Transfer the mixture into the prepared baking dish. Sprinkle the remaining 1/4 cup of Gruyère over the top, followed by an even layer of the seasoned breadcrumbs.

  12. 12

    Bake for 20-25 minutes, or until the sauce is bubbling around the edges and the breadcrumb topping is a deep golden brown.

  13. 13

    Remove from the oven and let it rest for 5-10 minutes before serving; this allows the sauce to set slightly.

💡 Chef's Tips

Don't skip the squeezing: Chard holds a surprising amount of water which can break your sauce if not removed. Use fresh nutmeg: The pre-ground stuff lacks the floral aromatics that make a Mornay sauce truly sing. Variety is key: If you use Rainbow Chard, the stalks will provide beautiful flecks of pink and yellow throughout the dish. Texture control: If you prefer a crunchier top, use Panko breadcrumbs instead of fresh sourdough. Make ahead: You can assemble the dish (without the crumbs) up to a day in advance and refrigerate; just add 10 minutes to the bake time.

🍽️ Serving Suggestions

Pair with a crisp, dry white wine like a Chablis or Sauvignon Blanc to cut through the richness. Serve as a side to roasted chicken or a pan-seared ribeye steak. Accompany with a simple green salad dressed in a sharp lemon vinaigrette. For a vegetarian feast, serve alongside roasted root vegetables and a wild rice pilaf.