Irish Stew

How very rarely one eats a good Irish stew – so often there is too much liquid or it is spoiled by the inclusion of carrots or barley. Eliza Acton says that the potatoes should be cooked to a mash, but I prefer to do as suggested by Paul and Jeanne Rankin of Roscoffs, Belfast, and use half of the potatoes to thicken the stew and the other half