I have just sown some tuberous chervil Chaerophyllum Bulbosum. This is a root vegetable with a chestnutty earthy taste. Seeds can be sown in the Autumn or in the Spring after a period of stratification ( they need a good 8 weeks of cold to germinate ). The tubers will grow over the summer months and can be harvested in the Autumn/winter but benefit from a period of frost. The great thing about these tubers is that once harvested the flavour actually improves with a period of storage. A great vegetable to add to your array of winter roots. The seeds have a very short viability, much like parsnip seeds so be sure to get fresh seed each year. Once you start growing your own, you will be able to collect and re-sow from your own stock.