Cut the hard boiled eggs in half lengthwise down the middle. Scoop out the egg yolks and place them in a medium-sized mixing bowl.
Add in the mayonnaise, Dijon, and lemon juice. Mash with a fork until smooth. Add in a bit of salt and freshly ground black pepper
Take half of the mixture and put it into a piping bag with a star tip. Pipe the yolk mixture into half of the egg whites. Alternatively, you can spoon the mixture in, if you do not have a piping bag. Garnish with the black caviar and the Ikura (salmon roe).
Mash in the avocado to the other half of the yolk mixture, and then add in the sliced scallions. Fill the other half of the egg whites with this mixture. Garnish with the smoked salmon and dill.