Preheat oven to 375 degrees.
Cook pasta according to package directions. Set aside.
Steam lobsters over boiling water for about 3 minutes until meat turns white rather than translucent. Remove meat from shell. Set aside to cool. Cut up meat into bite sized pieces.
Use water from steaming lobsters to make a lobster stock by adding lobster shells to the water and boiling for about 20 minutes.
In a separate pan, melt 5 tablespoons of butter over medium heat. Add salt, pepper, nutmeg, onion, shallot, and garlic and cook until translucent. Add flour and stir constantly until mixture has a creamy consistency. Slowly stir in milk, heavy cream and lobster broth. Remove from heat. Mix in cheese until combined.
Add pasta and lobster.
Transfer to a baking dish
Melt the remaining 2 tablespoons of butter, combine them with the fresh bread crumbs, and sprinkle on the top.
Put in oven on middle rack for 20 minutes.