Scrub potatoes; pierce several times with a fork. Place on a microwave-safe plate. Microwave, uncovered, on high for 15-17 minutes or until tender, turning once.
Meanwhile, in a large skillet, melt butter until over medium-high heat. Add the eggs; cook and stir until set. Remove and set aside.
When potatoes are cool enough to handle, cut each in half lengthwise. Scoop out pulp, leaving thin shells. In a large bowl, mash the pulp with Greek yogurt. Stir in the 1/4 cup cheese, 1/8 cup chives, parsley, salt, pepper, and egg. Spoon into potato shells.
Place on a baking sheet. Bake, uncovered, at 375° for 12-15 minutes or until heated through. Sprinkle with remaining cheese and chives. Serve with additional Greek yogurt if desired.