How to Make It
Preheat oven to 425°F with rack in lowest position. Brush a 10-inch cast-iron skillet with 1 tablespoon of the oil.
Toss potato slices with several grinds pepper, ½ teaspoon of the salt, and remaining 1 tablespoon oil; arrange in a circular pattern in prepared skillet, overlapping slightly so they cover bottom and up sides to form a crust. Bake until fork-tender and edges begin to brown, 16 to 18 minutes. Remove from oven.
Scatter ½ cup of the fontina over the bottom of the crust. Return to oven, and bake until cheese is melted, 2 to 3 minutes. Let cool about 10 minutes. Reduce oven temperature to 350°F.
While crust is baking, bring a large pot of salted water to a boil. Add kale and cook until tender, 3 to 4 minutes. Drain, wrap in a paper towel or dish towel, and squeeze dry.
Whisk together eggs, milk, sour cream, kale, several grinds of pepper, and remaining ½ cup fontina, and 1½ teaspoons salt in a medium bowl. Pour into cooled crust and sprinkle with Parmesan.
Bake until edges are slightly puffed and center is just set, 25 to 30 minutes. Adjust oven to broil with rack 6 inches from heat. Broil until top of quiche begins to brown, 3 to 4 minutes. Let cool 10 minutes before slicing.