Winter is a great time for brassicas. In fact, if you planted them in late Autumn you should be getting close to the harvest time. The brassica family of vegetables includes broccoli, broccolini, cabbage and cauliflower. They are easy enough to grow from seed, but growing from seedlings is more convenient (especially if you are planting them late)
Brassicas are generally slow but steady growers. They get very green and leafy over two months and then almost overnight, start to develop the veg bit you want. It then takes about 2 weeks for the brassicas to develop good- sized produce for harvest.
Check out our Brassica fact sheet: Brassicas