Has to be Cains mayo, and hot dog rolls so you can grill them to a golden brown with the salted butter.
Notice there is no lettuce, paprika, celery or any other filler. If anything else appears in your lobster roll, you have an inferior lobster roll.
steam the lobsters and shuck the meat
tear the meat into 1/2 inch chunks or so and mix with cains mayo
once lobster and mayo is chilled, butter each side of cheap hot dog rolls (the kind you tear apart)
you do not want to use any goddamn baguette or crusty overpowering roll
you want white bread tear apart soft hot dog rolls
once you butter the sides of the hot dog rolls with SALTED butter you pan brown the roll so its warm and golden brown
just barely browned but the roll should still be very soft
then load up your cool lobster/mayo filling into the warm soft buttery roll and you have yourself the perfect lobster roll
note- NO LETTUCE- NO CELERY-NO PAPRIKA- NO FANCY CRUSTY FRENCH ROLL