My method for boiling eggs so that you don't get that weird gray-green ring around the yolk, is to put the eggs in a pan, cover them with cool water by about one inch and bring to a boil. Cover the pan, remove from the heat and let them rest in the water for 12 minutes. They will be perfectly cooked.
Prepare an ice bath and transfer the eggs to it. Let rest for 10 minutes to assure they're cooled all the way through.
Carefully crack the egg shells and peel them. Slice the eggs in half, lengthwise and scoop out the yolk. Roughly chop the yolks with a knife and set aside.
Fill a pastry bag fitted with a star tip or a ziplock sandwich bag( as described above) with the deviled ham. If using a sandwich bag - seal the bag and trim off a corner so that you can pipe the filling into the egg.
Fill the eggs with the deviled ham (about 1 1/2-2 tablespoons per half egg). Garnish with chopped egg and/or other garnishes. Serve.
Notes
Can be made several hours in advance, loosely covered and refrigerated until ready to serve. Can be doubled or tripled.