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 al dente according to 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 roux.
04 - Gradually whisk in milk and heavy cream until smooth. Simmer for 3–4 minutes until mixture thickens enough to coat the back of a spoon. Remove from heat.
05 - Stir in shredded cheddar, Gruyère, and Parmesan cheeses until completely melted and smooth. Add Dijon mustard, smoked paprika, salt, and black pepper.
06 - Fold cooked macaroni and chopped lobster meat into the cheese sauce until evenly distributed. Transfer mixture to the prepared baking dish.
07 - Melt 2 tbsp butter in a skillet over medium heat. Add breadcrumbs and cook 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, covering the surface completely.
09 - Bake for 20–25 minutes until the top is golden brown and the sauce is bubbling around the edges. Let rest for 5 minutes before serving to allow the sauce to set.