In a large skillet over medium heat, saute the onion, carrot and celery in olive oil until golden. Add the lamb, rosemary, and bay leaf. When the lamb has browned, add the wine. Raise the heat and allow to evaporate. Add the tomato sauce, salt and pepper. Cover and lower the flame. Cook for the sauce for 90 minutes or so, stirring occasionally, until the meat is tender.
Prepare the Artichokes:
In the meantime, prepare the artichokes. For fresh artichokes: Remove the outer leaves and the inner fuzz. Peel the outer part of the stems. Cut into thin slices and place in a bowl cold water and lemon juice. Drain. For fresh or canned artichokes: In a skillet over medium heat, saute the garlic until slightly golden. Add the artichokes, salt, pepper, and the white wine. Cover and cook fresh artichokes for 10-15 minutes or until they are soft. (Cook canned artichokes until the wine is evaporated.)
Bring a large pot of salted water to a boil. Cook the pappardelle until al dente. Add to the skillet with the sauce. Add the artichokes. Mix well and serve with a generous sprinkle of Pecorino.