Place the lobster tail top shell up with the tail facing away from you. Use a pair of sharp kitchen scissors to cut straight down the middle of the lobster shell to the base of the tail.
Flip the lobster tail over onto its shell with the legs and clear-side facing up. Use your thumbs to push down into the lobster to break the ribs. (This will loosen the meat and allow you to pull it from the shell.)
Flip the lobster tail back over with the top shell up. The shell can be sharp, so carefully open the shell in the middle and run your fingers along the meat to loosen it from the shell.
Lift the meat from the shell keeping the base of the tail attached. Close the shell together underneath so the meat rests on top of it.
Repeat this butterfly method with each lobster tail and place them in a casserole dish. Preheat the oven to broil on high heat.
In a bowl, mix together the lemon juice, dijon mustard, salt, pepper, olive oil, garlic, and parsley.
Drizzle the sauce over the meat of each lobster tail.
Slice butter into squares and place two squares on each lobster tail.
Broil the lobster in an oven for about 10 minutes. As the lobster tails cook, the meat will turn white (slightly opaque in the center) and the shell will turn bright red.
Remove the dish from the oven and immediately plate the lobster tails onto a serving platter.
Quickly, pour the drippings from the pan into a small saucepan. Add 4 tablespoons of butter and bring to a simmer.
Add two spoonfuls of the sauce over each lobster tail. Place the remaining sauce into a dip bowl or ramekin on the side.
Serve & Enjoy!