Place the lobsters in a steamer or large pot, and steam for about 8-10 minutes until the shells turn bright red and the meat is opaque. Carefully remove and let cool slightly.
Once cooled enough to handle, crack open the shells and extract the lobster meat, focusing on the claws and tail for the best texture. Chop the meat into bite-sized chunks and set aside.
Slice the brioche buns in half and brush the cut sides with melted butter. Toast them in a skillet or under a broiler until golden brown and crispy on the edges. Remove and set aside.
Juice the lemon to obtain about 1 tablespoon of fresh lemon juice. In a bowl, mix the mayonnaise with the lemon juice, chopped herbs, and a pinch of smoked paprika or cayenne if using. Stir until smooth.
Add the chopped lobster meat to the mayonnaise mixture, gently folding until it’s evenly coated. Taste and adjust seasoning if needed—adding more lemon or herbs to brighten.
Pile a generous amount of the lobster mixture into the toasted buns, ensuring each sandwich is packed with tender lobster and flavorful dressing.
Finish by adding a few more chopped herbs on top, and serve immediately while the buns are still warm and crispy, with a squeeze of fresh lemon if desired.
