Preheat oven to 350F.
Boil pasta in a large pot of salted water until 1 minute shy of done. Drain well.
In meantime, with medium saucepan on medium-low heat, melt butter and add flour a little at a time, whisking constantly for 3 minutes to make a roux. Add half and half, a little at time, whisking to combine. Cook 3 minutes until sauce has thickened. Turn off heat. Add cheddar and gruyere, salt, nutmeg, cayenne and pepper. Stir until cheese is melted. Taste and adjust seasonings. Add cooked pasta to pan, stir to combine.
Butter 8 small ramekins or a large baking dish. Spoon pasta/cheese mixture into dish, up to 2/3 full. Bake in oven for 30 minutes.
While pasta is baking, melt 2 tbs butter in a medium skillet over medium heat. Once butter melts, turn off heat and add lobster meat, parmesan and panko bread crumbs. Toss to combine.
When pasta is done baking, remove from oven. Top pasta with a spoonful of lobster mixture. Set your oven rack to top 1/3 of oven, turn to broil and return ramekins to oven for 6-8 minutes. Lobster should be cooked through and a nice cheeesy crunchy crust will form.