Whisk together the mustard powder, water, vinegar and seasonings together in a medium bowl. Make sure there are no lumps.
Pour into a wide pan or pot and bring to a quick boil. Reduce the heat and simmer on medium-low heat for 10-15 minutes, stirring occasionally, or until you achieve your desired thickness. Think of your typical “yellow mustard”. I’ve made this recipe many times and the thickening time can vary, usually depending on the amount of heat.
Remove from heat and cool. Store in a sealable container in the refrigerator. It will thicken as it cools.
