I planted a row of fennel in September in the small coldframe. It is growing and looks quite happy. We're planning another fennel gratin for Christmas dinner.
A much faster growing winter veg is the radishes. I got HUGE ones this fall - bigger than eggs. Some are bigger than duck eggs. They're a handful. Cool weather radishes are less spicy than ones grown in the summer garden. We've been enjoying radish sandwiches made with leftover natural yeast pancakes. Mmmmm.