Preheat oven to 425F.
Butter a 9-inch pie plate and then coat it with the breadcrumbs. Swirl the breadcrumbs around the plate until you have an even coating and then tap out the excess.
Cover a baking sheet with foil; arrange the asparagus on the baking sheet and bake for 8 minutes.
Add the scallions and bake for 2 minutes more.
Collect 8 of the asparagus spears and set them aside to top the quiche and then cut up the remaining spears into 2 inch pieces.
Spread out the bacon on a baking sheet and bake for 14-16 minutes, or until brown and crispy. Remove the bacon to a paper towel lined plate.
Lower the heat of the oven to 350F.
Spread out the chopped asparagus and the scallions in the pie plate. Crumble the bacon and spread that out. Add the gruyere, parmesan, and parsley in an even layer.
Break the 5 eggs into a 4 cup measure and then add milk until you reach the 2 1/2 cup point on the measuring cup. This will be about 1 1/2 cups of milk.
Mix together the eggs and whole milk until well blended. Pour the custard over the ingredients in the pie plate. Tap the plate and give it a little shake to remove any air bubbles.
Then cut the reserved asparagus spears so they are a little shorter than the radius of the pie plate. Arrange them evenly around the top and press them into the custard a bit.
Bake for 40-45 minutes, or until the top is browned and the custard is set. The quiche will still jiggle in the middle but the edges will be puffed and firm.
Allow to cool until just warm or to room temperature. Then cut and serve.