Some people like only mayonnaise or melted butter on their lobster rolls, but we love the added flavor that fresh herbs provide.
Stir together lobster and mayonnaise. Stir in chives and tarragon (if desired), and lemon juice; season with salt and pepper. Refrigerate, covered, while preparing rolls, or up to 2 hours.
Heat a large heavy skillet or griddle over medium heat until hot. Lightly brush outside of buns with butter; transfer to skillet. Cook, turning once, until golden brown, about 1 1/2 minutes per side.
Spoon about 1/2 cup lobster mixture into each bun. Serve immediately.