Hardboil eggs normally at a simmer and cook about 12 minutes. Drain and cool in cold water. Peel the eggs and then cut in half lengthwise. Remove the yolks and discard. (Our dogs love it when we have this recipe because they get the yolks).
Drain garbanzo beans, reserving 1/3 c liquid. In a food processor or blender, puree beans, parsley, mustard, lemon zest, garlic and pepper until smooth. Transfer to a bowl and stir in red onion and capers. Taste and adjust seasoning. Fill egg halves with about a tablespoon of filling and sprinkle with paprika.
Sometimes I add celery seed and often I substitute minced green onions for the red onion. Frequently I used fresh herbs such as lemon thyme or a little cilantro to replace part of the parsley. Another nice change is to add green peppercorn dijon mustard in place of the plain mustard. My husband like it when I add a little horseradish, but many people don't like that flavor.