Preheat oven to 375 degrees F. Line a baking sheet with parchment paper.
Make the galette dough. Combine the flour with salt and cold butter using a pastry cutter or two forks until the mixture resembles coarse sand. Slowly add the ice cold water, mixing just until the dough comes together. Shape the dough into a disc and wrap in plastic wrap. Chill the dough in the fridge for 30 minutes or until firm.
Meanwhile, prepare black pepper ricotta. Combine the ricotta with grated parmesan, olive oil, black pepper, and salt. Set aside.
Heat a medium saute pan over medium heat. Remove the casing from the chorizo and cook in the saute pan, rendering the fat, for about 3-4 minutes. Remove from heat and cool.
Thinly slice the delicata squash with the skin on into ¼ inch thick slices. Remove the seeds. Thinly slice the apple with the skin on into ¼ inch thick slices. Toss both the squash and apple with 1 tablespoon olive oil and season with salt and pepper.
Remove the galette dough from the fridge. Lightly dust a clean work counter with flour and roll out the dough until it's ¼ inch thick. Transfer the dough to the prepared baking sheet.
Spread the black pepper ricotta on the dough leaving a 1-inch border. Top the ricotta with the sliced delicata, sliced apple, and chorizo. Fold over the edges of the dough over the fillings and brush the edges with the egg wash. Bake the galette for 40-45 minutes or the edges of the crust are golden brown. Remove from the oven and let cool slightly.
Sprinkle extra grated parmesan, freshly cracked black pepper, and a drizzle of olive oil. Garnish with fresh oregano. Serve warm.