Three Onion Tart
|All purpose flour||1 1⁄2 Cup (24 tbs)|
|Ice water||5 Tablespoon|
|Dijon mustard||1 1⁄2 Tablespoon|
|Unsalted butter||5 Tablespoon|
|Yellow onions||4 Medium, chopped|
|Red onions||2 Medium, sliced|
|Gruyere cheese||1⁄4 Pound, grated|
|Heavy cream||1 Cup (16 tbs)|
|Ground pepper||1⁄4 Teaspoon|
1. Make the pastry: Place the flour, salt and butter in a large bowl. Using a pastry blender or two knives, cut the butter into the flour until the mixture resembles coarse meal. Quickly stir in 4 tablespoons of the ice water with a fork. If the dough does not hold together easily when squeezed, blend in as much as 1 tablespoon more of ice water. Do not over mix. Pat the dough into a flat round about 6 inches in diameter; wrap in waxed paper and refrigerate for at least 30 minutes.
2. Preheat the oven to 425°. Place the pastry dough between two sheets of wax paper and roll it into a 12-inch round. Line an 11-inch quiche pan with the pastry, fitting it carefully into the pan without stretching. Prick the dough all over with a fork and fit a piece of aluminum foil into the pastry shell. Fill the foil with dried beans or rice and bake for 15 minutes.
3. Remove the pastry shell from the oven; remove the foil and beans or rice. Brush the interior of the pastry shell with the mustard and return it to the oven for 5 minutes to crisp the shell. Remove and reduce the oven temperature to 350°.
4. Make the filling: In a large skillet, melt 3 tablespoons of the butter over low heat and cook the yellow onions, stirring, until they are soft but not brown, about 5 minutes. Transfer the onions to a plate.
5. Melt 1 more tablespoon of the butter in the skillet. Add a layer of red onion slices and cook over moderate heat until they are slightly colored on the underside. (Do not disturb the slices or they may separate into rings.) Remove with a slotted spoon and set aside. Repeat with the remaining onion slices and butter.
6. Layer the yellow onions over the pastry shell and sprinkle the cheese evenly over them. Arrange the red onion slices on top, cooked-sides up, leaving a 1-inch border around the edge.
7. Add the remaining 1 tablespoon of butter to the skillet and cook the white onions for 2 minutes, tossing them so that they cook on all sides. Sprinkle the sugar over them and, tossing again, cook them until the sugar caramelizes, about 2 minutes. Reserving the glaze in the pan, remove the onions and cut them in half lengthwise. Arrange them, cut-sides down, around the edge of the tart. Place the tart on a baking sheet.
8. In a bowl, beat together the whole eggs, egg yolk, cream, salt and pepper until blended. Pour the mixture into the tart shell over the onions.
9. Bake the tart for 20 minutes. Reduce the temperature to 325° and bake for an additional 10 minutes, or until the filling is set.
10. Meanwhile, add 1/2 cup of water to the skillet and, stirring to blend in the caramelized sugar, reduce the liquid to about 2 tablespoons. When the tart is done, brush the surface with the glaze reserved in the skillet. Serve warm or at room temperature.