In a large skillet over medium-high heat, heat oil. Cook lamb until all pieces are brown on all sides. Remove with a slotted spoon; save for later. Drain most of the oil from the skillet. Add bell peppers, celery, tomatoes, potatoes, onion and garlic; cook over medium-high heat for about 5 minutes, stirring occasionally. Scrape the bottom of the skillet, adding lamb bits to the stew for flavor. Add stock, wine, tomato paste, paprika, bay leaves and lamb; bring to a boil. Reduce heat; cover and simmer until lamb is tender, about 1 hour. Remove lid and increase the heat slightly. Remove bay leaves. Cook, stirring to reduce sauce, about 15 minutes. Adjust seasonings.
Place stew in a serving dish; garnish with chopped parsley.