This famous lamb-and-potato stew topped with a dollop of mint sour cream fortified the Irish immigrants of Boston and was adopted by New England as its own.
In a large saucepan or Dutch oven combine lamb, broth, salt, pepper, and bay leaf. Bring to boiling; reduce heat. Cover and simmer for 30 minutes. Skim fat off meat mixture. Add potatoes, onions, carrots, thyme, and basil. Cover and simmer for 30 minutes more or until vegetables are tender. Discard bay leaf.
In a small bowl stir beer or water into flour. Stir into meat mixture. Cook and stir until thickened and bubbly. Cook and stir 1 minute more.
To serve, stir together the sour cream and mint. Dollop each serving with sour cream mixture. Makes 4 servings.
Combine sour cream and mint; cover and chill up to 24 hours.