I am following a low-carb diet, and would like to make corned beef hash at home with left over corned beef brisket. Onions are no problem, but I would prefer to avoid root vegetables, and potatoes in particular. What would make a good substitute, in terms of texture and taste?
Cauliflower might work. I've put cauliflower in a food processor to get it to a uniform small-ish size, and then stir-fried it until soft, as a low-carb substitute for rice. Maybe you could dice it into small pieces and do the same. Boiling or steaming instead of stir-frying may give you a softer potato-like texture.
Starchy is kind of the nature of hash. I am not sure that you would still have a hash if you eliminate the potatoes, but you should get something delicious in any case.
This low carb website suggests using cabbage in a hash-like dish.
Split pea & shallot mash from the GL diet book might work. Soak 225g split peas in cold water for 2 hours, drain place in pan & cover with water bring to boil & skim. Add 1 bay leaf & 6 sage leaves (I use thyme) simmer until tender, meanwhile fry off in olive oil 3 finely chopped shallots ( I use onion) add 2 tsps cummin + 1 clove minced garlic. Fry till soft. Drain split peas & retain water. Mix shallots with s/peas & remave bay leaf. process or blend adding water to suit the consistency you like.