Begin by boiling the potatoes until they are tender.
In a separate pot, cook the cabbage until softened.
In a skillet, fry the onions in butter or olive oil until they are golden.
Combine the boiled potatoes, cooked cabbage, and fried onions in a large bowl.
If desired, add ham to the mixture.
Season the mixture with salt and white pepper to taste.
Transfer the mixture to a baking dish and top it with mature cheddar cheese.
Bake in the oven at 200 degrees Celsius for 35 to 40 minutes, or until the top is golden.
