Put a 3-pound lobster—in front of someone, and you’ll be amazed at how much one person can eat. The water should be salted, which can be done in three ways: You can cook in seawater, which is nice; you can add seaweed, which is charming (and works); or you can use salt, as most of us do. Other than that, lobsters don’t need much; I used to do melted but…