1 tablespoon chopped fresh thyme or rosemary leaves
Pinch of ground nutmeg
Salt and freshly ground black pepper
1 bag frozen peas, thawed
3 large russet potatoes, cut into chunks
½ to 1 cup half-and-half
Melt about 2 tablespoons of the butter in a large Dutch oven (or crock pot)
Saute the lamb in batches until brown on all sides, adding a bit more butter if needed as you go.
Transfer the cooked lamb to a platter as it browns.
Add the carrots and leeks and cook until soft
Return the lamb and any accumulated juices to the pot.
Sprinkle with the flour and stir for 1 minute.
Whisk in the broth, Worcestershire sauce, thyme, nutmeg, and salt & pepper. Cook until thickened, about 45 minutes. Stir in the peas and remove from heat.
Meanwhile, boil the potatoes in a pot of salted water until tender. Drain and put in mixing bowl. And the remaining butter (reserving 1 tablespoon), the half-and-half (as needed), and salt and pepper and mash until smooth.
Preheat oven to 375. Top the lamb mixture in the Dutch oven with the mashed potatoes. Cut the remaining 1 tablespoon butter into small bits and scatter over the potatoes. Bake uncovered for about 30 minutes, or until golden and bubbling. Serve hot.