In a sauce pan, saute the onion in butter until soft. Add the sherry, cook for 1 minute. Add the heated half and half, spices, and bring to a slow boil. Add the roux to thicken. Then, blend in the Fontiago cheese. In a buttered casserole dish, add the cooked lobster meat. Top with the sauce and then top with the Romano and bread crumbs. Broil for 3-4 minutes, until lightly browned. Serve over pasta or rice and enjoy.