Thinly sliced russet potatoes absorb the richly flavored custard as it bakes and give this quiche its layered texture.
Prepare Buttery Flaky Pastry.
Preheat oven 350°. Bring potatoes, 1 tsp. salt, and water to cover to a boil in a large skillet over medium-high heat; cook 5 to 7 minutes or until tender. Drain potatoes, and pat dry with paper towels. Cool 10 minutes.
Cook onions in boiling salted water to cover in a small saucepan 2 to 3 minutes or until tender. Drain well, and press between paper towels.
Stir together parsley and next 2 ingredients in a small bowl.
Whisk together half-and-half, next 4 ingredients, half of parsley mixture, and remaining 1/2 tsp. salt.
Spread half of potatoes in bottom of pastry crust. Top with half of Gruyère cheese, half of cooked onions, and half of egg mixture; repeat layers once. Sprinkle with Parmesan cheese.
Bake at 350° on an aluminum foil-lined baking sheet 40 to 45 minutes or until center is set. Let stand 10 minutes. Sprinkle with remaining parsley mixture. Serve warm or at room temperature.
We made this and it was awesome. Flavors blended well and the appearance was quite a nice addition to the meal.