In a large skillet, heat the olive oil under medium high heat. Add about 1/2 of the lobster meat. Saute for about 3-5 minutes. Add the carrots, celery, onion, and garlic. Saute for about 5 minutes, or until vegetables start to soften.
Deglaze pan with brandy and (if using a gas stove) slowly tip pan away from you to allow for whiskey to catch fire. Alternatively (if you don't want to risk it, or if you have an electric stove), you can light a match and carefully light on fire. Allow alcohol to extinguish on it's own and then add wine. Reduce for about 5 minutes or so.
Add tomato paste and hand crush the whole tomatoes. Cook for about 3-5 minutes longer. Add in heavy cream, thyme, parsley, tarragon, and bay leaf. Bring to a boil, and lower heat to a simmer for about 20 minutes. Turn off heat and let cool for about 10-15 minutes. Remove bay leaf after cooling period is done.
Using an immersion blender, puree the mixture until you get a smooth texture of the lobster cream. I like a little bit of chunk in there so mine was not entirely silky smooth. Season with salt and pepper to taste.
Prepare the macaroni to al dente in a pot of salted boiling water. Drain and return to pot. Add remaining lobster meat and lobster cream. Mix well. Season with salt and pepper, if needed.
Pour mixture into large glass baking dish. Grate enough of the Gruyere cheese to form an even layer for the topping. Broil in oven until cheese is nice and browned. Serve immediately!