In a small bowl, add the mayonnaise, chopped chives, lime juice, and season well with the sea salt and black pepper. Stir the ingredients until combined.
Spread some of the prepared mayonnaise onto each bottom bread slice. Then, top the bread with alternating pieces of the lobster, cucumber, and cilantro. Finish with the remaining bread slices, and serve.
Cooked and peeled prawns are delicious substitutions for the lobster.