01 - Preheat your oven to 375°F (190°C). Lightly grease a 2-quart baking dish.
02 - Cook elbow macaroni or cavatappi in well-salted boiling water until it reaches the al dente stage. Drain thoroughly and set aside.
03 - Melt 1 tablespoon of butter in a skillet over medium heat. Add the chopped lobster meat and sauté gently for 1-2 minutes until just warmed through. Remove from heat and reserve.
04 - In a large saucepan, melt 3 tablespoons of butter over medium heat. Whisk in the all-purpose flour and cook for 1 minute, stirring constantly, to form a roux.
05 - Gradually whisk the whole milk and heavy cream into the roux until the mixture is smooth. Continue to cook, whisking frequently, for 3-5 minutes until the sauce begins to thicken.
06 - Reduce the heat to low. Stir in the shredded sharp white cheddar, Gruyère, and grated Parmesan cheeses, along with the Dijon mustard, garlic powder, cayenne pepper, salt, and black pepper. Continue stirring until all cheeses are fully melted and the sauce is smooth.
07 - Gently fold the cooked pasta and the sautéed lobster into the cheese sauce, ensuring everything is well combined.
08 - Pour the macaroni and lobster mixture into the prepared baking dish.
09 - In a separate bowl, combine the melted butter, panko breadcrumbs, chopped fresh dill, lemon zest, and a pinch of sea salt. Mix thoroughly.
10 - Evenly sprinkle the dill butter topping mixture over the macaroni. Bake in the preheated oven for 20-25 minutes, or until the topping is golden brown and the edges of the mac and cheese are bubbling.
11 - Allow the dish to rest for 5 minutes. Garnish with finely sliced fresh chives and serve with lemon wedges on the side, if desired.