Melt the butter in a sauté pan over medium heat. Add the asparagus and leek, and sauté for 8 minutes, stirring occasionally, until the asparagus is slightly tender. Season with 1/8 teaspoon of the salt and pepper.
In a medium bowl, whisk together the eggs, cottage cheese, and milk. Season with 1/8 teaspoon of the salt and pepper.
Place the prepared pie crust on a baking sheet (to avoid any spillage while baking). Add the Gruyere cheese, asparagus, and leeks, and top with the egg mixture.
Bake at 350 degrees for 50-60 minutes. Let the quiche sit for 10-15 minutes before serving.