In a medium pot, bring 4 quarts of water to a boil. Season with tbsp. of salt, then add lobster shells. Boil for 10 minutes. Remove lobster shells, and add pasta and cook according to package instructions, until al dente. Drain.
Slice lobster tail meat into pieces. Set aside.
Preheat oven to 350 degrees.
In a large skillet, heat 6 tbsp. butter over medium low heat. Once butter has melted, add flour and whisk until no visible lumps are present, and a smooth, creamy roux is formed.
Gradually whisk in evaporated milk and half & half. Stir in 1/2 tsp of salt, onion powder, garlic powder, paprika, ground mustard and pepper. Add brie cubes and whisk until cheese is melted. Add 1 cup of the white cheddar, and 1 cup of mild cheddar. Whisk until all cheeses are melted. Turn off heat.
In a small skillet, heat 2 tbsp. butter. Add lobster meat, and sauté until meat has turned pink.
Add cooked pasta and lobster to cheese mixture, and combine. Top with remaining cheese. Here you have two options, you can transfer to a buttered dish, or bake in the skillet. Bake in preheated oven for 20 minutes, or until cheese on top is melted and slightly browned.
Let rest for at least 10 minutes, and garnish with chives. Serve warm.
