Arrange the ham: Cut the fully cooked ham into thick slices if it isn’t pre-sliced. Nestle the slices on top of the onions, overlapping them slightly but keeping them mostly in a single layer so the heat circulates well. Spoon some of the loose onions up around the sides of the ham slices if you like.
Ham slices arranged over onions in the slow cooker
Ham slices arranged over onions in the slow cooker
Cover and cook: Place the lid on the slow cooker and cook on LOW for 5 to 7 hours, or on HIGH for 3 to 4 hours. The ham should be heated through and very tender, and the onions should be soft, translucent, and richly caramelized in their own juices and the melted brown sugar.
Rest and slice: Turn the slow cooker to WARM or off and let the ham rest in the juices for about 10 minutes. If the ham was in larger pieces, slice it into thick, serving-size slices at this point, returning them briefly to the juices so they stay moist.
Serve: To serve, lift the thick slices of ham from the slow cooker and arrange them on a platter or plate. Spoon plenty of the sweet caramelized onions and pan juices over the top or into shallow bowls, letting the ham sit in the juices just as it does in the slow cooker.
Served ham slices with caramelized onions and juices
Served ham slices with caramelized onions and juices
Variations & Tips
For a slightly different sweetness, you can swap the light brown sugar for dark brown sugar (for deeper molasses notes) or use half brown sugar and half honey, keeping the total to 1/2 cup so you still stay within the spirit of a minimal-ingredient dish. If you prefer a saltier profile, choose a less-sweet ham; for a more traditional Midwestern flavor, a slightly sweet city ham works beautifully. To add very subtle complexity without adding more ingredients, you can choose a smoked ham, which will lend a gentle smokiness to the onions and juices.
