3 slices of lean bacon, cut crosswise into 1/4-inch strips
2 large onions, quartered lengthwise and very thinly sliced crosswise (about
1/4 teaspoon ground cumin
Pinch of cayenne pepper
Pinch of cloves
Pinch of nutmeg
Flaky Pie Dough
2 large eggs
2 tablespoons all-purpose flour
1 cup heavy cream
Freshly ground black pepper
1/4 cup shredded imported Swiss cheese
Preheat the oven to 350°. In a large heavy saucepan, cook the bacon over moderately high heat, stirring often, until translucent, 2 to 3 minutes. Add the onions, cumin, cayenne, cloves, nutmeg and 1/4 teaspoon salt and cook until the onions soften slightly. Reduce the heat to moderately low and cook, stirring often, until the onions are very soft butt not browned, about 30 minutes. Remove from the heat and let cool to room temperature.
Meanwhile, roll out the Flaky Pie Dough to a 1/8-inch-thick round and transfer it to a 9 1/2-inch fluted tart pan with a removable bottom. Trim the edges. Prick the bottom of the dough with a fork and line with the foil and pie weights or dried beans. Bake the shell for about 15 minutes, or until slightly browned around the edges. Remove the foil and the weights and bake the shell for 10 to 15 minutes longer, or until the bottom is golden brown and completely dry.
In a medium bowl, whisk the eggs with the flour until smooth. Whisk in the cream, then stir in the onion mixture. Season with 1 teaspoon salt and 1/2 teaspoon pepper. Pour the filling into the baked shell and sprinkle the shredded cheese on top. Bake for 30 to 35 minutes, or until the top is golden brown and the custard is set. Let cool slightly before serving.
The tart can be refrigerated for up to 2 days. Reheat it slowly in a 325° oven until warmed through.