How to Make It
Make the crust In a food processor, pulse the 2 cups of flour with the sugar and salt. Add the butter and pulse until the mixture resembles coarse meal. Drizzle the ice water all over the mixture and pulse until the dough just starts to come together. Scrape the dough out onto a work surface, gather up any crumbs and pat the dough into a disk. Wrap in plastic and refrigerate until well chilled, about 1 hour.
Make the filling Preheat the oven to 425°. In a large skillet, melt 1 tablespoon of the butter in 1 tablespoon of the olive oil. Add the radicchio and a pinch each of salt and pepper and cook over moderately high heat, tossing, until just starting to wilt, about 2 minutes. Stir in the honey and vinegar. Transfer to a large bowl.
In the skillet, melt 1/2 tablespoon of the butter in 1/2 tablespoon of the olive oil. Add half of the endive and a pinch each of salt and pepper. Cook over moderately high heat, tossing, until browned in spots and just starting to wilt, about 2 minutes. Transfer to the large bowl. Repeat with the remaining butter, olive oil and endive. Let cool.
In a medium bowl, mix the ricotta with the 1/4 cup of Parmesan, the crème fraîche, egg yolk, lemon zest, lemon juice, 1/2 teaspoon of salt and 1/4 teaspoon of pepper.
On a lightly floured work surface, roll out the dough to a 14-inch round. Slide the pastry onto a parchment paper–lined baking sheet. Spread the ricotta mixture evenly on the pastry, leaving a 1-inch border all around. Scatter the cooled radicchio and endive on the ricotta mixture, then fold the pastry edge up over the vegetables to create a border.
Brush the edge of the galette with the egg wash and bake for about 25 minutes, until the pastry is nicely browned and crisp. Let cool slightly, then sprinkle with shredded Parmesan and pistachios. Serve warm or at room temperature.