01 - Preheat oven to 375°F. Grease a 2-quart baking dish with butter or cooking spray.
02 - Bring a large pot of salted water to boil. Cook elbow macaroni until just al dente, about 1-2 minutes less than package directions. Drain thoroughly and set aside.
03 - In a medium saucepan over medium heat, melt 3 tbsp butter. Whisk in flour and cook for 1 minute, stirring constantly to form a smooth paste.
04 - Gradually pour in milk and heavy cream while whisking continuously to prevent lumps. Bring to a gentle simmer and cook for 3-4 minutes until sauce thickens enough to coat the back of a spoon.
05 - Remove saucepan from heat. Stir in sharp cheddar, Gruyère, and Parmesan cheeses until completely melted and smooth. Add Dijon mustard, smoked paprika, salt, and black pepper, whisking to combine.
06 - Add cooked macaroni and chopped lobster meat to the cheese sauce. Gently fold together until pasta and lobster are evenly coated.
07 - Pour the lobster macaroni mixture into the prepared baking dish, spreading it into an even layer.
08 - In a skillet over medium heat, melt 2 tbsp butter. Add fresh breadcrumbs and toast for 2-3 minutes until golden brown, stirring frequently. Remove from heat and stir in parsley, chives, lemon zest, and garlic powder.
09 - Sprinkle the herbed breadcrumb mixture evenly over the macaroni and cheese, covering the surface completely.
10 - Bake for 20-25 minutes until the top is golden brown and the sauce is bubbling around the edges. Remove from oven and let rest for 5 minutes before serving to allow the sauce to set slightly.