If you want to make your own pastry, you can go to Smitten Kitchen for her recipe, use your own, or use a store-bought pie crust. It is much quicker to make using refrigerated rolled pie crusts. Preheat oven to 375 degrees F. Cut squash in half. Scoop out seeds and place on a baking sheet with skin down, orange "meat" up. Brush tops with olive oil and sprinkle 1/2 teaspoon salt on top. Bake about 30 minutes until tender. Set aside to cool slightly. While squash is roasting, melt butter in a heavy skillet and cook onion over low heat with the remaining half-teaspoon of salt and pinch of sugar, stirring occasionally, until soft and lightly golden brown, about 20 minutes. Stir in cayenne. Increase the oven temperature to 400 degrees F. Mix squash, caramelized onions, cheese, and sage together in a bowl. To assemble pie/galette, roll out pie crust and place on an ungreased baking sheet. (If making your own, roll it out on a floured surface and then transfer to baking sheet.) Spread squash, onions, cheese and herb mixture over the dough, leaving a 1 1/2-inch border. Fold the border over the squash, onion and cheese mixture, pleating the edge to make it fit. The center will be open. Bake until golden brown, 30 to 40 minutes. Remove from the oven, let stand for 5 minutes. Cut into wedges and serve hot, warm or at room temperature.