1 C dry ground mustard
1 C apple cider vinegar (we prefer the raw, unfiltered variety)
2-3 T Truvia or 1/4-1/3 C honey
1/2 tsp. salt
1/4 tsp. black pepper
Combine all ingredients in a saucepan; whisk to blend. Simmer over medium heat for 5-10 minutes. Pour into a clean jar. This will last for several weeks.
The hot mustard flavor comes through VERY strong initially, but it mellows out a bit over the next day or two. If it's still too strong for you, add a bit more sweetener to balance it out. It took a few adjustments to get it just where we liked it.