Butternut Squash Gratin

• 2 medium-size butternut squash
• 2 tablespoons hazelnut oil plus extra as needed
• 1 cup <

Peel the squash and cut into enough ¼-inch-thick slices to fill 3 cups. Heat the 2 tablespoons of hazelnut oil in a large skillet over medium heat. Add the squash and cook gently on each side until golden; or, if you prefer, parboil the slices 3 to 4 minutes in lightly salted boiling water.

Preheat the oven to