Place the eggs in a pot with cold water and gently bring to a boil.
When the water boils, cover the pot, turn off the heat and let stand for exactly 7 minutes.
After 7 minutes, drain the hot water and rinse with icy cold water for a minute. This keeps the yolk from turning grey.
Peel the eggs, chop them roughly and place in a bowl.
Combine the eggs, relish, mayonnaise (optional) and mustard.
Add the tuna to egg mixture and stir again.
Season to taste with black pepper. Adjust the texture if necessary with more mayonnaise.
Put 1-2 handfuls of Romaine lettuce in a bowl and top with 1/4 egg/tuna mixture.