In a small bowl, add the beer mustard, honey, brown sugar and vinegar, whisking to combine. If the ham is still warm, using gloves, rub the mustard glaze into all the cuts, creating an even coating all around the leg. Next, pierce a clove into the center of each diamond and repeat, covering the whole ham. Place into the oven, uncovered for 40 – 45 minutes, or until the surface is bubbling and starting to caramelize. Let cool for 15 – 20 minutes before carving and service.