Cut each hard-boiled egg in half, and place the yolks in a medium bowl. Set the egg whites on a serving plate, cut side up.
Add mayo, kimchi, vinegar, sesame oil and green onion to the egg yolks, and using a fork, mash and mix to combine. Season to taste with salt and additional vinegar if needed. Flavors should be bright!
Transfer yolk mixture to a small zip top bag. Seal the bag, then cut off one of the bottom tips. Pipe the yolk mixture into the wells of each egg white. Finish by topping each egg with a little chopped kimchi, chive and black sesame seeds. Enjoy immediately!