In a bowl, combine Maille Honey Dijon Mustard, melted butter, apple cider vinegar, salt, and pepper. Whisk until well combined.
Brush the ham steaks with the honey mustard glaze.
Place the ham steaks on the grill over direct heat. Close the grill and cook for 4 minutes. Flip the ham steaks and baste once more. Close the grill and cook for 4 minutes. Transfer the ham steaks to a plate.