8 tablespoons unsalted butter, cold, cut into small pieces
4 tablespoons ice water
1 tablespoon chopped fresh parsley
Filling:
2 tablespoons olive oil, divided
½ cup diced yellow onion
1 pound red chard, stalks cut into thin matchsticks and leaves roughly chopped
2 tablespoons chopped fresh parsley, divided
2 garlic cloves, minced
½ teaspoon dried chili flakes
1 teaspoon sea salt, divided
½ teaspoon freshly ground black pepper, divided
4 ounces oyster mushrooms, torn into pieces
1 cup fromage blanc
½ cup grated Pecorino Romano cheese
1 egg yolk
Finish:
1 egg beaten with 1 teaspoon heavy cream or half-and-half
Instructions
Prepare the crust:
In a large bowl, combine the flour, cornmeal, sugar and salt. Add the butter and rub it into the flour mixture with your fingertips until it resembles coarse meal. Add water and parsley and mix with a fork until the ingredients start to come together. Then use your hands to lightly knead the dough in the bowl until it forms a ball. Flatten the ball into a disc, wrap in plastic and chill in the refrigerator for at least 1 hour.
Prepare the filling:
Heat 1 tablespoon olive oil in a fry pan over medium heat. Add onion and chard stalks and cook, stirring occasionally, until tender, 3-4 minutes. Add chard leaves and cook, stirring occasionally, until just barely wilted, about 2 minutes. Transfer vegetables to a medium bowl. Add 1 tablespoon parsley, garlic, chili flakes, ½ teaspoon salt and ¼ teaspoon pepper and stir until combined. Set aside.
In a medium bowl, combine the fromage blanc, Pecorino Romano cheese, egg yolk, remaining 1 tablespoon parsley, remaining ½ teaspoon salt and remaining ¼ teaspoon pepper; whisk until smooth.
Assemble and bake the galette:
Remove the dough from the refrigerator and let it sit for 5 minutes. On a lightly floured work surface, roll out dough to a 14" circle. Carefully transfer the dough to a baking sheet lined with parchment paper.