Name: Sweet Potato Swiss Chard Gratin
Total time: 1 h 45 min
Ingredients: 2 tablespoons cold-pressed extra-virgin olive oil; 2 shallots , minced; Salt and pepper; 2 pounds Swiss chard , stemmed and cut into ½-inch-wide strips; 3 garlic cloves , minced; 2 teaspoons minced fresh thyme or ¾ teaspoon dried; 1/3 cup homemade or low-sodium chicken or vegetable broth; 1/3 cup water; 1/3 cup dry white wine; 3 pounds sweet potatoes , peeled and sliced ⅛ inch thick; 2 ounces Parmesan cheese , grated (1 cup)

Why This Recipe Works

We first replaced the regular spuds with their sweet, bright-orange relative, a rich source of vitamin A. But sweet potatoes got their name for a reason, so to mitigate some of their sweetness, we turned to earthy, slightly bitter Swiss chard, packed full of vitamin K, which we sautéed with shallots, garlic, and thyme. We shingled half the sliced potatoes along the bottom of a gratin dish, added our chard, then layered on the remaining potatoes. Pouring a mix of broth, water, and wine over the vegetables encouraged the potatoes to cook evenly and imparted a welcome savoriness—no cream necessary. We topped the potatoes with Parmesan; just 2 ounces provided the salty richness we wanted. Covering the gratin dish for the first 20 minutes of baking gave the potatoes enough time to cook through, then we uncovered the dish to ensure the excess liquid could evaporate and the cheesy topping could brown and form the perfect light crust.

Before You Begin

Slicing the potatoes ⅛ inch thick is crucial for the success of this dish; use a mandoline or a food processor fitted with a ⅛-inch-thick slicing blade.

Instructions

Adjust oven rack to middle position and heat oven to 350 degrees. Heat oil in Dutch oven over medium-high heat until shimmering. Add shallots and ¼ teaspoon salt and cook until shallots are softened, about 2 minutes. Stir in chard and cook until wilted, about 2 minutes. Stir in garlic, thyme, and ¾ teaspoon pepper and cook until fragrant, about 30 seconds; transfer to bowl.

Add broth, water, wine, and ¼ teaspoon salt to now-empty pot and bring to simmer over medium-high heat. Remove pot from heat and cover to keep warm.

Shingle half of potatoes evenly into 3-quart gratin dish (or 13 by 9-inch baking dish). Spread wilted chard mixture evenly over potatoes, then shingle remaining potatoes over top. Pour broth mixture evenly over top, and sprinkle with Parmesan.

Cover dish with aluminum foil and bake for 20 minutes. Uncover, and continue to bake until gratin is golden and feels tender when poked with paring knife, 40 to 50 minutes. Let cool for 10 minutes, season with salt and pepper to taste, and serve.