Egg Gratin with Swiss chard and Cherry Tomatoes
Serves 4 to 6.
From “The Complete Vegetarian,” by America’s Test Kitchen.
• 3 tbsp. unsalted butter, plus extra for dish, divided
• 2 1/2 oz. Manchego cheese, grated (1 1/4 c.), divided
• 8 oz. cherry tomatoes
• Salt and pepper
• 2 garlic cloves, minced
• 8 oz. Swiss chard, stemmed and cut into 1/2‑in. pieces
• 2 tbsp. cornstarch
• 1 1/4 c. half-and-half
• 4 eggs
Adjust 1 oven rack to middle position and the second rack 6 inches from the broiler element. Heat oven to 350 degrees. Grease bottom and sides of broiler-safe 2‑quart gratin dish with butter and sprinkle 1/4 cup Manchego evenly over the bottom and sides of the dish.
Melt 1 tablespoon butter in a 10‑inch nonstick skillet over medium-low heat. Add tomatoes, 1/2 teaspoon salt, and 1/4 teaspoon pepper and cook until tomatoes begin to break down and release their liquid, 3 to 5 minutes; transfer tomatoes to prepared dish.
Wipe out now-empty skillet with paper towels and melt remaining 2 tablespoons butter over medium-low heat. Add garlic and cook, stirring occasionally, until lightly golden, about 2 minutes. Stir in chard and increase heat to medium-high. Cover and cook until chard is wilted but still bright green, about 2 minutes. Uncover and cook, stirring frequently, until liquid evaporates, about 1 minute. Transfer chard to gratin dish and spread evenly over tomatoes.
Whisk cornstarch and 1/2 teaspoon salt together in medium bowl. Whisk in half-and-half, eggs, and 3/4 cup Manchego until thoroughly combined. Pour egg mixture over tomatoes and greens. Sprinkle with remaining 1/4 cup Manchego. Bake gratin on middle rack until toothpick inserted in center comes out clean, 30 to 40 minutes, rotating dish halfway through baking. Remove gratin from oven.
Heat broiler. Broil gratin on top rack until cheese is golden brown, about 2 minutes. Let gratin cool until custard has set up, about 5 minutes. Serve.