The Nasturtium seeds are best gathered on a dry day, when they are young and soft and come off the plant easily. Give them a rinse and place in a one litre glass jar.
To 480ml of vinegar add 25g celtic sea salt and 25g pickling spice tied together in a muslin bag and boil for 5 minutes. Add this liquid to the jar of nasturtiums making sure to cover them completely. Screw lid on. It is suggested that these are set aside for several months to a year before use. These are hot and spicy.
I have yet to also try grinding dried nasturtium seeds and adding to the pepper grinder.