To our joy, my daughter Tae heard about a seafood wholesale outlet nearby, and on our first visit we discovered very affordable cooked 1¼-pound lobsters. After a happy feast, the time came to deal with a mountain of shells. Wastehaters that we both are, she decided to make lobster bisque. Pretty exotic, right? Yes, but really not that difficult!
First, Tae sweated (in order words, sauteed on low flame to pull the moisture out) some minced onions, celery, and carrots in olive oil at the bottom of a very large pot, then she put in all the shells, covered them with chicken broth (vegetable stock would have been OK, too), and simmered it all for a couple of hours, after which she strained it into a large bowl.
Meanwhile, in another large pot she made a roux (white creamy sauce) and cooked it gently until it turned light brown. She poured in the strained lobster liquid and stirred until it came to a gentle simmer. Ten minutes later came time to check for taste and consistency. Since it was a bit too liquid, she added a couple of tablespoonfuls of cornstarch (previously dissolved in some cold liquid) and allowed the bisque to simmer some more to cook the starch. Then she splashed in some white wine, sherry, and cognac. Last, she added enough heavy cream to make a nice consistency. No more cooking after that, lest the delicate flavor disappear.
You could also make this soup with shrimp shells. It is really a soup fit for royalty and freezes easily, so you can pull it out for your honored guests any time!