3 pounds lamb, well-trimmed and cut into bite size pieces
2 teaspoons salt
1 teaspoon freshly ground black pepper
3 tablespoons olive oil
2 medium onions, cut into 1/2-inch chunks
8 cloves garlic, peeled and smashed
3 tablespoons tomato paste
1/4 cup flour
1 cup Stout beer
3 cups beef broth
2 cups water, plus 2 tablespoons more for cooking onions and garlic
1 bay leaf
1 small sprig fresh rosemary
3 teaspoons sugar
4 large carrots, peeled and cut into bite size pieces
1 pound new potatoes, cut into bite size pieces
1 cup frozen green peas
Pat the lamb dry and season with salt and pepper. In a Dutch oven, heat oil over medium-high heat until hot. Brown the lamb. Transfer the browned meat to large bowl and set aside.
Add the onions, garlic and 2 tablespoons of water to the pot. Cook until the onions are soft, stirring with a wooden spoon to scrape any brown bits from the bottom of pan, about 5 minutes.
Stir in the tomato paste and cook a few minutes more. Add the lamb with its juices back to the pan and sprinkle with flour. Stir with a wooden spoon until the flour is blended, 1-2 minutes.
Add the Stout, beef broth, water, bay leaf, rosemary sprig and sugar. Stir with a wooden spoon and bring to a boil. Cover the pot with a lid, turn the heat down to low and simmer for one hour and twenty minutes.
Add the carrots and potatoes to the stew, then cover and continue simmering until the vegetables are tender, 30-40 minutes. (Be sure to stir a few times to prevent vegetables from sticking to bottom.)
Remove the bay leaf and rosemary sprig. Add the frozen peas and cook until the peas are warmed through.