1. Place 2 tablespoons of the butter in a large-deep saucepan or casserole over medium heat. When it melts, add the onion, garlic, carrot, bay leaf, and thyme and cook, stirring, until the onion softens, 5 to 10 minutes.

2. Add the lobster bodies and, if they are uncooked, cook, stirring, until they turn red, about 10 minutes (if they're already cooked, cook, stirring, about 5 minutes.

3. Add the wine and tomatoes and turn the heat to medium-high. Bring to a boil, then turn down the heat to low, cover, and cook for 10 minutes.

4. Add the stock, turn the heat to high, and bring back to a boil. Once again, turn the heat to low and cover; cook for 20 minutes. Remove the bay leaf and thyme sprigs. Remove the lobster shells, crack them if necessary, and pick off any meat you find. Return the bits of meat to the soup (reserve any large pieces of meat you have for the final addition below).

5. Pass the soup through a food mill or puree it in a blender or food processor. (You may prepare the soup in advance up to this point.Cover, refrigerate for up to 2 days, and reheat before proceeding.)Return the soup to the pot and bring to a boil. Add the remaining butter, in bits, until it melts. Add the cream and any bits of lobster meat and heat through. Season with salt and pepper, garnish, and serve.

* Shopping Tip:
There are two good ways to obtain lobster bodies, one is to save them from a lobster feast. The other is to get them from fish markets, which either give them away or charge minimally.