Prep the pie crust at least 30 minutes in advance. In a large bowl, whisk together flour, celery seed, and salt. Add cold butter, and using a pastry blender or your fingers, cut the butter into the flour until there are only small, peas sizes pieces of butter visible in the flour. Next add cold water, 1 tablespoon at a time, mixing with your hand or a spatula after each addition, until the dough begins to stick together. Using your hands, form the dough into a flat disk. Cover with plastic wrap, and chill at least 30 minutes.
Preheat oven to 400°F. Toss asparagus with 1 tablespoon olive oil and a generous sprinkle of salt and pepper. Roast until slightly fork tender, about 10-15 minutes. Once the asparagus is out of the oven, raise the temp to 425°F.
Meanwhile, add 1 tablespoon olive oil over medium heat in a medium skillet. Add leeks and a pinch of salt, and sauté until softened and slightly browned, about 5 minutes. Add frozen peas, and sauté until thawed completely, another 2-3 minutes. Remove from the heat and let cool slightly.
On a floured surface, roll out the dough until it's large enough to line a 9 inch round pie pan. Line pie pan with pie dough, prick bottom with a fork several times, then crumble half of the goat cheese and spread along bottom. Next add leeks and peas and spread evenly throughout the dish. Then crumble the rest of the goat cheese. Lastly arrange asparagus on top of the fillings.
Add eggs to a mixing bowl, and beat slightly. Then add heavy cream, 1 teaspoon salt, sugar, and cayenne and whisk to combine. Pour egg mixture evenly over other ingredients in the pie dish.
Bake at 425°F for 15 minutes. Then lower the temperature to 300°F and bake 35-40 minutes, or until set with just a slight wobble in the middle.
Remove from the oven and let sit 10 minutes before slicing.