We're out of stock of these till next season. Why not grow Red Baron instead?
Unlike the majority of vegetables, the flavour of home grown onions is much the same as shop bought ones, so they're not something I would prioritise if you're short of space or time.
Nevertheless, they're a very easy and rewarding crop to grow, particularly when grown from sets (baby onions). Sturon has firm juicy flesh and is a classic keeper. Harvest the entire crop in late summer and you'll have a supply of onions right through the winter.