- Preheat oven to 325ºF. Place ham on a cutting board and blot off excess moisture. Peel off skin and use a sharp knife to remove excess fat, leaving a thin layer. Score fat every inch with knife in one direction. Repeat in opposite direction.
- Place orange slices, rosemary and water in the bottom of a 9×13 oven safe pan. Place ham on top and cover with parchment paper and aluminum foil. Bake for 1 hour and 15 minutes
- While ham bakes, stir together orange sauce, Dijon mustard and garlic in a small bowl. In a large mixing bowl, combine potatoes, cabbage, olive oil, sea salt and black pepper. Toss to coat.
- Remove ham from oven and carefully transfer to a plate. Discard foil, parchment paper, water, orange slices and rosemary. Increase oven temperature to 400ºF.
- Arrange potatoes and cabbage in baking pan and place ham on top. Brush ham with half of glaze. Return to oven for 30 minutes, uncovered. Baste with glaze once more and return to oven for 30 minutes or until internal temperature reaches 140ºF. Tent ham with aluminum foil if the top starts to burn. Remove from oven and allow ham to rest at room temperature 20 minutes before slicing. Serve alongside roasted cabbage and potatoes.