1. Add all ingredients (except the vinegar) into a large non-reactive pan over medium-low heat.2. Whisk and stir until it cooks down to a thick paste (about 15-30 minutes).3. Once it cooks down to a thick paste, whisk in the white vinegar and let it cook down further until you have your desired consistency (5-10 minutes).4. Once it has thickened to your liking, remove from heat and let cool to room temperature. Once cool, you can transfer to an airtight container and store in your fridge for up to 3 months.
Note: The mustard will be super strong and pungent the first couple days. Over time, the flavors will mellow.