Preheat oven to 375° F.
Place garlic in aluminum foil, drizzle with olive oil, wrap, and roast in oven for 45 minutes. Remove roasted garlic from cloves. Smash cloves to create paste.
Cook macaroni according to package directions and reserve in a large bowl.
Cook bacon until crisp and place on paper towels; reserve 1 tablespoon of bacon fat. Chop bacon.
Prepare topping by stirring together breadcrumbs, bacon, 2 ounces Gruyère and 2 tablespoons butter. Set aside.
Sauté shallots in a large pan over low heat in reserved bacon fat for 1 minute. Add remaining butter and continue to sauté shallots until translucent.
Whisk in flour and cook for 1 - 2 additional minutes. Increase heat to medium, add milk and 2 tablespoons of roasted garlic paste while stirring constantly with a whisk.
Continue to stir sauce until thickened; remove from heat, season with salt and pepper, and stir in havarti and remaining Gruyère .
Pour sauce over macaroni, add lobster meat, and stir to combine. Transfer mixture to baking dish or individual ramekins. Sprinkle with topping, cover with foil and bake for 15 minutes. Remove foil and continue baking until sauce is bubbly and topping has browned.