SWEET ONION TART WITH BACON Locally grown Walla Walla onions are large, sweet and juicy. In this tart, they are cooked very slowly over low heat to bring out their flavor. Any sweet onion, such as Vidalia or Maui, would make an acceptable substitute. PASTRY 2 sticks (1/2 pound) frozen unsalted butter 1 2/3 cups all-purpose flour 1 tablespoon plus 1 teaspoon sugar 1/2 teaspoon salt 2/3 cup heavy cream FILLING 1/2 pound thickly sliced bacon 3 large sweet onions, such as Walla Walla, thinly sliced Salt and freshly ground black pepper 7 large eggs 1 cup heavy cream 1/2 cup shredded Gruyère cheese (2 ounces) 1 1/2 tablespoons freshly grated Parmesan cheese 1 teaspoon minced rosemary 1/4 teaspoon cayenne pepper Pinch of freshly grated nutmeg

MAKE THE PASTRY: Working over a medium bowl, grate the butter on the large holes of a box grater; freeze. In another bowl, combine the flour, sugar and salt. Using a pastry blender or 2 knives, cut in the butter until the mixture resembles coarse meal. Add the cream and mix with a fork until a dough forms. Turn the dough out onto a lightly floured work surface and pat into a disk. Wrap in plastic and refrigerate until chilled, at least 1 hour.

MEANWHILE, MAKE THE FILLING: In a large skillet, cook the bacon over moderate heat, turning, until crisp, about 6 minutes. Drain the bacon on paper towels and cut into 1-inch pieces. Pour off all but 3 tablespoons of the fat from the skillet. Add the onions to the skillet and cook over low heat, until caramelized and very tender, about 1 hour. Season with salt and pepper and let cool.

Preheat the oven to 425°F. On a lightly florued surface, roll out the dough in half and transfer it to an 11-inch fluted tart pan with a removable bottom. Unfold the dough and press it into the pan. Trim the overhang. Freeze the tart shell until firm, about 10 minutes.

Line the tart shell with foil and fill with pie weights or dried beans. Bake for about 30 minutes, or until the pastry starts to dry. Remove the foil and weights and bake about about 3 minutes longer, or until golden brown. Transfer the tart shell to a rack to cool.

Turn the oven down to 375°F. In a bowl, whisk the eggs with the cream. Stir in the bacon, onions, Gruyère, Parmesan, rosemary, cayenne and nutmeg. Season with 1/2 teaspoon salt and 1/4 teaspoon pepper. Pour the filling into the tart shell and bake for 25 minutes, or until the custard is set. Transfer to a rack to cool slightly. Unmold and serve.

Makes one 11-inch tart.

[Food & Wine, November 2000]