Combine equal parts yellow and brown mustard seeds in a medium bowl. Add enough water and apple cider vinegar to fully submerge the seeds. Soak for 12 to 24 hours.

Mix together paprika, cayenne pepper, turmeric, and a pinch of salt in a small bowl for the spice blend.

Drain the soaked mustard seeds and transfer them to a blender or food processor. Add the spice blend and honey or brown sugar. Blend to desired consistency.

Pour the blended mixture into a small saucepan; heat over medium-low, stirring constantly until thickened, about 10 minutes.

Remove from heat, allow to cool slightly, then blend again to achieve the perfect texture.

Let cool to room temperature, then transfer to an airtight jar and store in the refrigerator. Let sit for at least a day before using.