How to Make It
Bring a large pot of water to a boil. Plunge the lobsters in, head first, and cook until bright red all over, about 12 minutes. Transfer the lobsters to a bowl.
Crack the lobster claws and knuckles and remove the meat. Twist the tails from the bodies and slit the undersides lengthwise with scissors. Remove the meat and discard the black intestinal vein that runs along the tail. Cut the lobster into 1/2-inch pieces.
In a large bowl, mix together the mayonnaise, lemon juice, mustard and tarragon. Fold in the lobster meat and cucumber and season with Tabasco, salt and pepper. Cover and refrigerate the lobster salad for at least 30 minutes. Just before serving, mix in the scallions. Generously fill each hot-dog bun with lobster salad and serve.