Preheat the oven to broil and place the oven rack close to the broiler, about 3-4 inches away. Line a baking sheet with foil and season the lobster tails with avocado oil spray, salt and freshly ground black pepper.
Meanwhile, preheat a cast-iron pan to medium-high heat until smoking. Once smoking add ½ tbsp avocado oil. Add the filets to start browning.
Place your lobster tails under the broiler and cook for at least 7-10 minutes. Or until cooked through.
While the lobster tails are broiling, continue to sear the filets on both sides until nicely browned including the sides. Remember, you are just trying to get a nice crust on the outside–the filets are already cooked to the right internal temperature. This should take about 4 minutes in total.
Once the filets are browned, remove them from the pan and allow them to rest for 5 minutes.
Once the lobster tails are done, spread the spicy serrano-cilantro butter on top of the flesh.
To serve, top the filets with hollandaise and garnish with chives. Serve broiled lobster tails alongside and enjoy!