Peel the cooled hard boiled eggs.Cut the eggs in half horizontally, and set the yolks aside.In a bowl, mash the avocado and 2 whole egg yolks; discard the rest.Mix in lime juice, red onion, jalapeño, cilantro, salt and pepper and adjust to taste. Gently fold in tomato.Scoop heaping spoonfuls of the guacamole into the 12 halved eggs.Sprinkle with a little chile powder for color and arrange on a platter.