Layers of thinly sliced squash, silky onions, and a creamy cheese sauce bake up to bubbly, golden-brown perfection in this elegant side dish.
Scalloped Butternut Squash with Caramelized Onions
Makes 6 to 8 servings
- 2 pounds sweet onions, chopped
- 4 tablespoons unsalted butter
- ¼ cup all-purpose flour
- 1 (12-ounce) can evaporated milk
- 1 cup low-sodium chicken broth
- ¾ teaspoon kosher salt
- ½ teaspoon ground black pepper
- 1 tablespoon chopped fresh thyme
- 1 tablespoon chopped fresh sage
- 1 (2½-pound) butternut squash, peeled, halved, and sliced into ⅛-inch-thick half-moons
- 1 cup grated Parmesan cheese
- Garnish: fresh thyme, fresh sage, ground black pepper
- In a 10-inch cast-iron skillet, cook onion over medium-low heat, stirring occasionally, until very tender and golden brown, about 1 hour. Remove from skillet; wipe skillet clean.
- Preheat oven to 375°. Spray 10-inch cast-iron skillet with cooking spray.
- In a small cast-iron Dutch oven, melt butter over medium heat. Whisk in flour; cook, whisking constantly, for 2 minutes. Gradually whisk in milk, broth, salt, and black pepper until smooth; cook, whisking frequently, until sauce thickens, 5 to 7 minutes. Remove from heat; whisk in thyme and sage.
- Arrange one-third of squash slices in concentric circles in prepared pan. Top with one-third of onions, one-third of sauce, and one-third of cheese. Repeat layers twice. Spray a piece of foil with cooking spray; cover skillet with foil, spray side down.
- Bake for 30 minutes. Uncover and bake until squash is tender, sauce is bubbling, and cheese is browned, about 30 minutes more. Let stand for 15 minutes before serving. Garnish with thyme, sage, and pepper, if desired.