Rainbow Chard & Shallot Gratin Recipe
Creamy, cheesy, leafy greens with tender shallots make for the ultimate comfort food side dish!
How to Make the Best Rainbow Chard & Shallot Gratin
This rainbow chard and shallot gratin is the ultimate comfort food side dish—creamy, cheesy, and loaded with vibrant leafy greens. The combination of tender rainbow chard, caramelized shallots, and a silky béchamel sauce makes this a showstopper that’s elegant enough for holiday dinners but easy enough for weeknight meals.
What makes this gratin special is the care taken in preparing the chard. Blanching it first removes any bitterness and ensures a tender texture in the final dish, while the colorful stems add a beautiful visual pop. The shallots, when cooked slowly over gentle heat, become sweet and mellow—a perfect complement to the earthiness of the greens.
The béchamel sauce is the real star here, coating every leaf with creamy, cheesy goodness. Made from a simple roux and whole milk, with a generous addition of Gruyere and Parmesan, it bakes into a golden, bubbling top that’s absolutely irresistible. Make this ahead of time for dinner parties or holidays—it’s the perfect make-ahead side dish that reheats beautifully.
Rainbow Chard & Shallot Gratin
Creamy, cheesy, leafy greens with tender shallots make for the ultimate comfort food side dish!
Ingredients
Main Ingredients
Sauce
Instructions
Prep
- Chop the greens. Trim most of the stem off the chard and chop the leaves and stems. The greens are the star of the dish, but the stems add a burst of color.
- Blanch the greens. In a large pot of boiling water, blanch rainbow chard in batches, cooking until wilted—about 1 minute. Transfer to an ice bath immediately. Continue until all the rainbow chard is blanched. Following the ice bath, squeeze the chard thoroughly in a kitchen towel.
Cook
- Sauté the vegetables. In a deep-sided sauté pan, heat the olive oil on medium-low heat, add the shallots and season with about ¼ teaspoon salt. Cook while occasionally stirring so the shallots do not burn, about 2 minutes. Add in the garlic, cook 1 more minute. Remove from heat, stir in the rainbow chard and then transfer the vegetables to a side dish while you prepare the sauce. Butter a 9x13 inch baking dish and preheat the oven to 425°F.
- Make the sauce. In a large saucepan, melt the butter over medium heat, then stir in the flour to form the roux. The texture will be like a thick paste. Gradually pour in ⅓ of the milk, whisking constantly to remove any clumps while the mixture thickens. Repeat a second and third time until all the milk is incorporated and the sauce is smooth. Continue whisking until sauce begins to boil. Reduce heat to low and cook about 15 minutes, occasionally stirring. The sauce should be thick and creamy.
- Make the gratin. Whisk in the Parmesan cheese, ½ cup Gruyere cheese, and nutmeg. Combine the sauce with the chard and shallots, season with salt and pepper to taste. Transfer the rainbow chard and shallot mixture to the baking dish. Sprinkle with the remaining Gruyere cheese.
- Bake. Bake in the upper third of the oven for about 25 to 30 minutes, until bubbling and the top is golden brown. Let the dish rest about 8 to 10 minutes before serving to allow the creamy sauce to set.
Notes
- This dish can be made ahead and refrigerated before baking.
- The chard can be blanched and squeezed up to a day in advance.