Boil the lobster for 7 minutes, then shock in an ice bath.

Remove the tail, claw, and knuckle meat. Clean the tail of its digestive tract and slice into bite-size pieces.

Reserve the large claw for garnish - set all other meat aside for the mac.

Clean the lobster shells: remove any innards, guts, and antennas.

Add the cleaned shells to a blender and pulse to break them down.

Pour in the warm clarified butter and blend until finely ground.

Transfer to a saucepan over medium-low heat. Add the peppercorns, bay leaf, and garlic.

Steep gently for about 10 minutes, then strain through cheesecloth or a fine mesh sieve.

Press or squeeze out as much butter as possible. Discard solids. Set lobster butter aside.

In a large skillet over medium heat, melt 3 tbsp of the lobster butter.

Add the shallot with a pinch of salt and cook for 1 minute.

Add sliced garlic and cook until fragrant, about 30 seconds.

Add flour and whisk until combined. Stir on medium heat for 2 minutes.

Whisk in the milk slowly and simmer, stirring frequently, until thickened.

Lower the heat and season to taste with salt.

Slowly fold in two-thirds of the grated cheese. Stir until smooth.

Boil pasta in well-salted water according to package instructions.

Drain and add directly to the cheese sauce, stirring to combine.

Use pasta water as needed to loosen the sauce.

Grease a 6” cast iron skillet with lobster butter.

Spoon in a layer of mac and cheese halfway up.

Add the lobster chunks and a generous layer of cheese.

Top with remaining mac and cheese and finish with the rest of the grated cheese.

Broil until golden brown and bubbling on top.

Warm the reserved lobster claw gently in lobster butter until heated through.

Garnish the mac with chives, the claw, and a drizzle of warm lobster butter for shine.