Warm Stilton and Mushroom Galette
1 1/4 cups all-purpose flour, frozen in the freezer 1 hour
1/4 teaspoon salt
8 tablespoons ice cold butter, cut into 12 pieces
4 tablespoons sour cream
2 teaspoons lemon juice
1/2 cup ice water
1/4 ounce dry porcini mushrooms
1 cup boiling water
2 tablespoons unsalted butter
6 green onions, white and green, thinly sliced
1/2 teaspoon freshly chopped rosemary
1/2 teaspoon freshly chopped thyme
1 pound cultivated or button mushrooms, thinly sliced
4 ounces Stilton or other blue-veined cheese
Place the flour and salt in a food processor and pulse two times to combine. Add the butter and pulse several times until most of the mixture is the size of bread crumbs with a few pieces the size of peas. Dump the mixture out onto the work surface in a pile. Spread out the pile a little. Make a well in the center. Whisk together the sour cream, lemon juice and water and add half of the liquid to the well. With your fingertips, mix the liquid with the dry until large lumps hold together. Remove the large lumps and repeat with the remaining liquid. Use as much of the liquid as needed to hold the dough together. Let rest in the refrigerator, 1 hour.
Preheat oven to 400ºF. Place the dry porcini mushrooms in a small bowl, cover with boiling water and let sit 30 minutes. Drain the mushrooms and reserve the liquid for another use. Finely mince the mushrooms and reserve.
In a large frying pan over medium heat, melt the butter. Add the green onions and cook, stirring occasionally, until soft, 5 minutes. Add the rosemary and thyme and continue to cook 1 minute. Increase the heat to high, add the fresh and minced dried mushrooms and cook until the mushrooms are soft and the liquid from the mushrooms has completely evaporated, 8 to 10 minutes. Remove from the pan and cool.
Roll the dough on a floured surface to make a 12-inch circle. Place on a baking sheet. In a bowl, combine the Stilton and mushrooms. Spread the mixture over the dough, leaving a 1 1/2-inch border around the edge. Fold the uncovered edge of the pastry over the mushrooms and cheese, pleating it to make it fit. There will be an opening in the center of the tart. Bake until golden brown, 30 to 40 minutes. After 5 minutes, slide the galette onto a serving plate. Serve hot, warm or room temperature.