You'll get more flavour out of fennel seeds by grinding or dry frying them. To grind, either pound in a pestle and mortar, put them in a sealed bag and bash with a rolling pin or whizz up in a small, clean coffee grinder. To dry fry, heat up a pan, tip in the seeds and, over a medium heat, brown for a couple of minutes, tossing them around the pan frequently.
Kept in an airtight container in a cool, dark place, fennel seeds will last for up to two years.
Use to flavour fish, meat and vegetable dishes, as well as breads and chutneys. You can also chew the whole seeds as a breath-freshener, and they're believed to aid digestion, too.