Joe, talk about going off the subject! However, beetroot is gorgeous roasted, as are tomatoes (but tomatoes don't work so well if put with other roasting veg.) - and as so many have said above, parsnips! Sweet potatoes and celeriac are good too. Beetroot needs to be boiled in its skin, and then peeled first. And some veg. is better if it's par-boiled for 5 mins. first. Your method is fine.

Barbara