Place the cut potatoes in large pot of salted water. Bring to a boil; simmer, covered, for 15 minutes, or until tender.
While the potatoes are cooking, saute the pancetta and onions in a large saute pan with 1 tablespoon of butter. Add the cabbage and water and saute until the cabbage is tender and a bit caramelized.
Drain the potatoes. Place in a large bowl and mash with a potato masher. Stir in the milk, butter and cabbage. Add salt and pepper to taste.
Notes
If you are preparing this recipe as GLUTEN-FREE, just be sure to use a brand of pancetta that is known to be GF. You can also use prosciutto in place of pancetta.