Preheat oven to 350 degrees F. Prepare quiche filling by heating butter in a sauté pan or skillet over medium heat. Add onions and sauté until translucent. Stir in asparagus. Season with and fresh ground black pepper. Remove mixture from heat and cool. Prepare custard by combining eggs, cream, nutmeg, parsley, salt and pepper in a bowl, mix thoroughly. Place cooled asparagus filling in pie shell and spread evenly. Top with cheeses. Pour in custard and gently tap quiche on work surface to remove "air pockets". Bake at 350 degrees F for 45 minutes or until golden brown and cooked through. Test by piercing with a small knife. If knife comes out clean, the quiche is done. Cool quiche for 15 - 20 minutes before slicing.