Makes 8 servings.
1 cup all-purpose flour
1/2 teaspoon salt
1/3 cup plus 1 tablespoon chilled solid vegetable shortening
2 tablespoons cold water
2 tablespoons butter
1 onion, finely chopped
1 1/2 cups (16 ounces) shredded Swiss cheese
1 cup chopped cooked ham
2 large eggs
2 large egg yolks
1/2 cup half-and-half
1/2 cup heavy cream
Pinch of salt
Pinch of cayenne pepper
Pinch of ground nutmeg
To prepare pastry, in a medium bowl, mix together flour and salt. Using a pastry blender or 2 knives, cut shortening into flour mixture until coarse crumbs form.
Add water, 1 tablespoon at a time, tossing with a fork, until a dough forms. Shape dough into a disk, wrap in plastic wrap, and chill for 30 minutes.
On a floured surface, using a floured rolling pin, roll dough into a 10-inch circle. Fit into a 9-inch quiche or pie pan. Trim edges.
To prepare filling, in a skillet, melt butter over medium heat. Add onion; cook, stirring occasionally, until softened, 6 to 8 minutes. Remove from heat; cool.
Preheat oven to 375 degrees F. Sprinkle 3/4 cup of cheese over crust. Top with onion, then ham. Sprinkle with remaining cheese.
Whisk together eggs, egg yolks, half-and-half, cream, salt, cayenne and nutmeg. Pour egg mixture over ham and cheese.
Bake quiche until golden and custard is set, 35 to 45 minutes. Let rest for 5 minutes before serving.