Heat the oven to 425ºF. Meanwhile, add enough water to a 9x13-inch baking dish to cover the bottom (about ¾ cup). Butterfly the lobster tails.

Pat 4 (about 8-ounce) lobster tails dry and arrange hard shell-side up on a cutting board. Using kitchen shears and starting from the thicker end, cut lengthwise through the top shell on each tail, stopping when you get to the end of the tail.

Using your fingers, gently pry the meat away from the top shell on either side by working your thumb between the shell and the meat. Gently pry the meat up and away from the bottom shell. All the meat should come out of the shell easily at this point. Place the meat back in the shell. (If the meat sticks to the shell, boil the lobster tails in water for 3 minutes so the meat separates easily from the shell before proceeding with the next step. Check for doneness after 10 minutes in Step 6.)

Using a chef’s knife or the kitchen shears, cut the tail meat in half lengthwise from where the shell was split, stopping when you get the bottom shell (do not cut through the bottom shell). Open the tail up like a book, flip it over, and gently press down to flatten if needed (cover with a towel before flattening if the shell is sharp).

Place the tails flesh-side up in a single layer in the baking dish. Cover the baking dish tightly with aluminum foil.

Bake until the flesh is firm when pressed, cooked through, and the internal temperature registers 135 to 140ºF, 20 to 27 minutes. Meanwhile, halve 1 medium lemon. Cut one half into 4 wedges for serving. Juice the remaining half until you have 2 teaspoons.

About 5 minutes before the lobster is ready, melt 4 tablespoons unsalted butter in a small saucepan over medium heat. Add the 2 finely chopped garlic cloves and cook until fragrant but not browned, about 20 seconds. Remove the saucepan from the heat. Add 1 tablespoon finely chopped fresh parsley leaves, 2 teaspoons lemon juice, and ½ teaspoon kosher salt, and stir to combine.

When the lobster is ready, transfer to serving plates and drizzle with the lemon garlic butter. Serve with the lemon wedges.