Caramelized Onion and Blue Cheese Tart

Dough2 cups all-purpose flourPinch of sea salt, finely ground1 1/2 sticks unsalted butter, well chilled 1/4 cup shortening, chilled 1/4 cup ice waterFilling2 tablespoons unsalted butter2 tablespoons olive oil4 medium onions, sliced or chopped 1/4 cup sherry 1/2 cup heavy cream2 egg yolks3 ounces blue cheese, crumbled2 tablespoons fresh thyme 1/2 teaspoon cracked black pepperFor the crust: Place flour and salt in food processor. Cut up butter and shortening into small pieces and add to processor; blend mixture until it is crumbly and you can feel the butter in little pieces throughout the flour. Continue to pulse while adding cold water and blend until mixture almost forms a ball. (A little crumbly is OK, just work it together with your hands.)Turn out on work surface and flatten into a disc. Wrap in plastic and refrigerate at least 2 hours before using.Roll out dough to fit 9-inch tart pan. Do not trim edges.For the tart: Heat oven to 400 degrees.Heat large sauté pan over medium heat; add butter and olive oil. When pan is hot add onions and cook until golden brown. Add sherry to deglaze pan, loosening browned bits from the bottom. Remove from heat and allow onions to cool before placing them in the tart shell.In a bowl, whisk together cream and egg yolks. Pour mixture over onions. Sprinkle with crumbled blue cheese and top with thyme and black pepper. Fold over any excess pastry to create an edge. Bake for 30 minutes or until crust is golden brown, cheese is bubbly and custard is set. Serve warm.Serves eight to 10.Chef's note: You may freeze this dough for up to six months. Thaw in refrigerator before use.Chef Cali Bergold, ChefCali