Lightly season lobster tails with salt and pepper. Place lobster tails in a FoodSaver’s vacuum seal bag with butter, tarragon sprig and garlic and vacuum seal.
Place bag in a water bath and set sous vide at 140˚F for 30 minutes.
While lobster tails cook, place a large pot of water over high heat. Once water comes to a boil add a small handful of salt and pasta to water. Boil pasta, stirring occasionally, until al dente. Drain and set aside.
Place a large skillet over medium heat and melt butter and oil. Add shallot, garlic and lobster shells and saute for about 2 minutes. Stir in tomato paste and tarragon and continue to saute for an additional 2 minutes.
Deglaze pan with brandy and cook until most liquid has evaporated.
Remove lobster shells and discard.
Stir cream into mixture and season with salt and pepper. Lower heat to medium-low and simmer sauce.
Remove lobster tails from water bath and vacuum seal bags and chop into bite sized pieces. Stir lobster pieces into sauce.
Add pasta to skillet and toss together until well coated. Adjust seasonings as needed.
Top pasta with sliced chives and serve.