Fill a medium size pot with tap water about halfway, then add about 1 teaspoon of salt. Heat the water to a rolling boil and add the lobster tails to the pot. Boil the tails for 5-7 minutes until the shell is bright red. Do not cover the pot. When ready, carefully remove the lobster tails from the pot using tongs, place them on a board, and let them rest for 5 minutes to allow the meat to absorb the moisture inside the shell.
Cut the lobster shell in half lengthwise and remove the meat from the lobster shell. Cut the lobster meat into ½-inch (1.3cm) pieces. Pat dry excess moisture off with a paper towel. Set aside.
Add mayonnaise, hot sauce, and garlic powder in a small mixing bowl. Mix well to thoroughly combine, then set it aside.
Melt half of your butter in a skillet over medium heat. Add lobster to the pan of melted butter and toss to coat. Cook until just warmed, 2-3 minutes (lobster meat is already cooked, so we're just warming it). Transfer the lobster to a medium bowl with a slotted spoon. Add spiced mayo, celery, chives, lemon juice, salt, and pepper, and mix to fully combine. Set aside.
Wipe your skillet clean with a paper towel, and melt the remaining butter over medium heat. Add buns to the melted butter, flat sides down, and toast for 1-2 minutes or until golden on both sides.
Open buns, place a lettuce leaf, spinach, or mixed veggies inside, then top with lobster-mayo mixture to fill the bun.
Sprinkle with fresh chives and serve immediately.