How to Make It
In a food processor, pulse the flour and salt. Add the butter pieces and pulse to the size of small peas. Sprinkle the ice water over the flour mixture and pulse until the pastry starts to come together.
Scrape the pastry out onto a work surface and knead gently a few times to form a cohesive dough. Flatten into a disk, wrap in plastic and refrigerate until thoroughly chilled and firm, about 1 hour.
Preheat the oven to 350°. In a 12-inch ovenproof skillet, melt the butter. Add the endives, cut sides down, and cook over moderately high heat until sizzling, about 2 minutes. Cover the skillet, transfer to the oven and bake for 25 minutes. Turn the endives cut sides up and season with salt and pepper. Cover and bake for about 20 minutes longer, until very tender.
Turn the endives cut side down. Cook over moderately high heat until browned, 2 minutes. Add the orange juice to the skillet and bring to a boil, then remove from the heat. Increase the oven temperature to 425°.
On a lightly floured work surface, roll the pastry out to a 12-inch round, about 1/4 inch thick. Lay the pastry over the endives in the skillet. Trim any overhang. Bake in the upper third of the oven for about 35 minutes, until the pastry is richly browned and crisp.
Set the skillet over high heat and shake gently to loosen the endives. Set a large plate upside-down on top of the pan, then carefully invert the tart onto the plate. Let cool slightly, then cut into wedges and serve warm.