CABBAGE AND ONION TORTA

Steps:

• To make the pastry, combine flours and 7 grams (1 1/2 teaspoons) salt in a large bowl. Using a pastry cutter or two forks, cut in butter until it forms coarse crumbs. Add 1 to 1 1/2 cups very cold water, working it in a few tablespoons at a time, until mixture just comes together. Form dough into a ball, cover with plastic, and refrigerate for at least 1 hour or overnight.
• Heat 2 tablespoons oil in a large skillet over medium-high heat. Add the onion and cook, stirring occasionally, until soft and lightly browned, about 10 minutes.
• Add 1 tablespoon oil and stir in cabbage, a handful at a time, waiting for each addition to wilt slightly before adding more. Season with 5 grams (1 teaspoon) salt and some pepper. Cook until cabbage is tender and any liquid has evaporated, about 7 to 10 minutes. Stir in vinegar and cook until evaporated, scraping up any browned bits from the bottom of the skillet. Transfer mixture to a bowl. Taste and add more salt, vinegar or both, as needed.
• Add remaining 1 tablespoon oil to skillet and stir in bread crumbs, garlic and thyme. Cook until bread crumbs begin to color, about 1 minute. Scrape into a bowl.
• Heat oven to 425 degrees. Oil a large baking sheet.
• On a floured surface, roll out dough into a 17-by-12-inch rectangle. Transfer to the baking sheet. With the long side facing you, spread half the bread crumbs evenly over right half of dough, leaving a 1/2-inch border. Top with half the cheese, then cover cheese with half the cabbage mixture. Repeat layers. Sprinkle ham over the top if desired.
• Dab edges of dough with water. Fold left half over filling and use the tines of a fork to seal edges. Brush crust with egg yolk. Using a knife, cut several slits in the center of the top crust. Transfer pie to oven and bake until crust is golden brown and firm, 40 to 50 minutes. Cool for at least 15 minutes before slicing and serving. Serve warm, or reheat before serving.