You can pickle them like capers or dry them and put them in a pepper mill to use like pepper.

Or if you want to grow them next spring, just keep them dry over winter.

put them in a paper envelop or paper bag and keep in a cool dark place until spring. having said that many fall to the ground in my garden and then they grow away all by them selves next year.

They do so here, Sbg, but I wasn't sure of the UK. Here, they grow in the winter, and the seeds lie dormant through the summer!