Butternut Squash and Escarole Gratin Recipe

DIRECTIONS

1. Butter a 6- to 8-cup baking dish. Set oven rack in upper third of oven and heat oven to 400F.
2. Bring 3 inches of water to boil in a large saucepan. Add escarole and cook, stirring, until tender, 3 to 5 minutes. Drain in a colander and rinse under cold running water. Gently squeeze to remove as much moisture as possible.
3. Melt 1 tablespoon of the butter in a medium nonstick skillet over medium-high heat. Add half of the squash and season with 1/4 teaspoon of the salt and 1/8 teaspoon of the pepper; cook, turning occasionally, until lightly browned and nearly tender, about 8 minutes. Transfer to baking dish. Repeat and reserve.
4. Melt remaining tablespoon butter in skillet over medium-low heat. Add leeks and season with remaining 1/4 teaspoon salt; cook, stirring, 3 minutes. Add water, cover and cook, stirring occasionally, until tender, about 3 minutes. Stir in escarole and cook until heated through; spoon over squash in baking dish.
5. Top with reserved squash.
6. Wipe out skillet. Combine cream, broth and thickener in skillet, whisking until blended. Cook over medium heat, stirring, until thickened, about 2 minutes. Remove from heat and stir in Gruyre until melted.
7. Pour sauce over vegetables, spreading evenly. Sprinkle Parmesan on top and bake until bubbly and golden brown on top, about 30 minutes. Let stand 10 minutes before serving.