Asparagus kale is a biennial vegetable reputed to be one of the tastiest of kales, and is treated more like a broccoli. The leaves have a more delicate flavour than cabbage or other kales and can be eaten through the winter even when picked frozen solid, but it is better left until the spring when the young flower shoots can be broken off, blanched and eaten like asparagus. Relatively dwarf, hardy and prolific.
Start the seeds off in a tray in spring and plant out when robust enough. In the first year it will produce edible leaves. Thin out if need be as they grow big next year. In the second year it will produce edible tender shoots in a similar way to purple sprouting broccoli. Keep cropping to make the plant produce more!