1Peel and quarter the potatoes, then boil in salted water until tender.
2Chop the leek and savoy cabbage, then wash and dry using a salad spinner.
3Mash the cooked, drained potatoes with butter and milk until smooth and creamy.
4Melt butter in a large pan and sauté the diced bacon until crisp.
5Add the prepared leeks and cabbage to the pan with the bacon. Season with black pepper, add the mustard, and pour in milk. Cook until the vegetables are tender.
6Fold the cabbage and bacon mixture into the mashed potatoes until well combined.