Preheat oven to 400°. Grease 8 muffin cups.
In a bowl, whisk egg, salt and pepper until blended; stir in potatoes and Asiago cheese. To form crusts, press about ¼ cup potato mixture onto bottom and up sides of each prepared muffin cup. Bake until light golden brown, 14-17 minutes.
For filling, in a small bowl, whisk eggs and chives until blended; stir in cheese and spinach. Spoon into crusts; top with bacon. Bake until a knife inserted in the center comes out clean, 6-8 minutes.
