Brush the potatoes well under cold running tap water and let them drain. I didn't peel them but go ahead if you want to! Chop the potatoes into smaller chunks and add them to a large pan. Cover with cold water, season with a pinch of salt and place the pan over high heat.
Cook the potatoes for 20 to 25 minutes or until tender. Right before the potatoes are done, transfer a tablespoon of the butter and the chopped garlic cloves to a high pan. Cook for 3 minutes.
Then add the sliced kale (or savoy cabbage).
Stirfry the kale for a couple of minutes. Season with a pinch of pepper and salt. Drain the potatoes and add them to the kale in the pan.
Mash the potatoes and kale up well. Add the mustard, the remaining butter and the whole milk.
Mash well again. Then check the seasoning and add extra pepper or salt to taste if necessary. Add the grated bologna sausage to the mash.
Stir firmly until the mash is well combined. Scoop the kale mash onto plates and serve hot.