Break off tough ends of asparagus and slice off scales with a vegetable peeler. Steam asparagus for 5 minutes in a pot of water, with lid on top; asparagus should be tender/crisp. Run under cold water, strain, and refrigerate.
Mix yogurt with dill, chives, mustard, salt, and pepper. Separate asparagus between 2 serving dishes and top with 2 tablespoons sauce and 1/2 egg.