1. Preheat grill to medium-high.
2. Lay lobster tails on a cutting board with the soft side of the shell facing up. Cut the tails in half lengthwise through the shell using kitchen shears, starting from the fan (see Kitchen Notes). Run your fingertips along the inside of the shell to loosen the meat in the shell. Brush the meat with oil.
3. Lay the tails on the grill, cut-side down, and cook until the meat is lightly charred and the shell is beginning to turn red, 5 to 6 minutes. Turn and continue grilling until the meat is opaque and cooked through and the shell is completely red, 2 to 4 minutes more. Transfer the lobster to a cutting board. Meanwhile, toast buns over indirect heat, 3 to 5 minutes.
4. While the lobster cools, bring a small pan of water to a boil. Cook snow peas until bright green, 1 minute. Drain, refresh under cold water and slice very thinly (almost shredded). When the lobster is cool enough to handle, remove the shell and coarsely chop the meat.
5. Mix celery, mayonnaise, lemon juice, shallot, mustard, tarragon, pepper, salt and garlic powder in a large bowl. Stir in the chopped lobster and snow peas. Divide the salad among the toasted buns.

Yield: 4 servings