Shake vinegar, olive oil, honey and mustard together in a jar.
Taste and season with salt and pepper to your liking.
Store in fridge if not using right away. If you store it in the fridge, the oil may harden. You can set it at room temperature for 15 minutes or so before using or you can remove the lid of the jar and microwave for 10-15 seconds, replace the cover, and shake.