These were once very common kitchen tools, and rather wide spread. The Eskimo woman's knife, the ulu or ooloo, is one of many built on these lines. The ulu can be used for much more than chopping, and I suspect their Colonial counterparts saw many uses as well. I have several in different patterns, and these were made by blacksmiths in some cases, by tool companies in others (notably Disston). There isn't a part of a stew that can't be done with this knife. Cuts stew meat into chunks quite handily, as well as mincing onions (or simply slicing them. There's a good deal of variation in their construction, since the only requirements are a handle centered over a curved blade. Nigella's two handled chopper is more restricted to chopping herbs and such -- and really does much better with a shallow wooden bowl.