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 macaroni until al dente according to package directions. Drain thoroughly and set aside.
03 - Melt 3 tbsp butter in a medium saucepan over medium heat. 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. Bring to a gentle simmer and cook for 3-4 minutes until mixture thickens enough to coat the back of a spoon.
05 - Remove from heat. Stir in cheddar, Gruyère, and Parmesan cheeses until completely melted and smooth. Add Dijon mustard, smoked paprika, salt, and black pepper.
06 - Add cooked macaroni and chopped lobster meat to the cheese sauce. Fold gently until evenly distributed. Transfer mixture to the prepared baking dish.
07 - Melt 2 tbsp butter in a skillet over medium heat. 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.
08 - Sprinkle herbed breadcrumb mixture evenly over the macaroni and cheese. Bake for 20-25 minutes until top is deeply golden and sauce is bubbling around edges.
09 - Let dish rest for 5 minutes before serving to allow sauce to set slightly. Serve hot while cheese is still gooey.