Clean and soak - Wash the seed pods well to remove any dirt (or critters). Picking out any hard or brown seed pods. Place them in a jar and cover with water, securing the lid. Leave them to soak in the fridge for 1–2 days, changing the water once (if you remember). This helps mellow out any bitterness.
Make the brine - In a small saucepan, gently heat the vinegar, water, salt and sugar until dissolved. Don’t boil it... just warm it enough to combine everything.
Drain and rinse the seed pods and pack them into a clean sterilised jar. Add mustard seeds, dill and chilli flakes if using (you could also add a bay leaf if you wanted).
Pour the cooled brine over the top until everything is fully covered.
Seal the jar and place it in the fridge. They’ll start to develop flavour within a few days, but I usually leave mine for 1 week before using.
