This deconstructed delicacy gets the star out of the bun and dresses it up in lemon butter. With a few plump brioche croutons on the side, the dish is complete.
Steam lobsters in a large pot, covered, for 14 minutes. Transfer to a plate; let cool. Remove meat from shells.
Whisk together 2 tablespoons of the butter, melted, with lemon juice; toss with meat. Cut brioche into 1 1/2-inch cubes. Melt remaining 2 tablespoons butter in a medium skillet. Toast bread until golden; toss with sea salt.
Divide meatand bread between 2 plates.Serve with lemon wedgesfor squeezing, and garnishwith fresh tarragon.