Prepare the pasta according to its instructions, ensuring it’s al dente when finished.
While the pasta is cooking, cut the butter into pats about 1/2 Tbsp each.
Add the milk, pats of butter, and flour to a 2-quart saucepan and whisk well till the flour is dissolved. Bring to a boil over medium heat, stirring constantly.
Allow the sauce to boil for 1 minute, stirring constantly, reducing the heat as needed to prevent scorching.
Remove the sauce from the heat. Whisk in the dry mustard, and the Vermont sharp cheddar, Gouda, and Gruyere cheeses, then whisk until smooth.
Add the sea or Kosher salt and white pepper to the sauce to taste.
Drain the pasta (be sure to toss it to get all the water from inside the noodles) and pour it into a large mixing bowl.
Fold a serving-spoon portion of the sauce with the warm lobster, enough to sauce the lobster meat with a thin coating.
Fold the remainder of the cheese sauce into the pasta.
Plate the Mac & Cheese topped with the sauced lobster meat, followed by the shredded Parmesan cheese.