For both versions, start by toasting the mustard seeds in a dry skillet over medium heat until they just start to pop, about 2-3 minutes.
Combine remaining ingredients in a saucepan and bring to a boil.
Pour toasted seeds into saucepan, reduce heat and simmer for 45 minutes, or until the seeds are tender enough to pop when bitten between your front teeth.
Pour mixture into small pint/250ml jar and allow to cool. Store in fridge for up to 3 months.
Notes
In addition to mustard seeds you could also create a blend with: coriander seeds, cumin seeds or fennel seeds.