Yam Quiche

Name: Yam Quiche
Ingredients: 1 1/4 cups all-purpose flour; 1/4 teaspoon kosher salt; 1 stick cold unsalted butter, cut into cubes; 3 to 4 tablespoons ice water; 1 1/2 pounds yams, peeled and cut into 1/2-inch dice; 2 tablespoons olive oil; Kosher salt; Pepper; 1 1/2 cups half-and-half; 6 large eggs; 1/8 teaspoon freshly grated nutmeg; 1 tablespoon unsalted butter; 1 cup chopped yellow onion; 1 tablespoon finely chopped sage; 5 ounces Swiss cheese, coarsely shredded (2 cups)