Place the potatoes into a pot of cold, salted water and bring to a boil. Reduce the heat and simmer until the potatoes are fork-tender.
While the potatoes are boiling, cook the bacon in a separate pan. Once cooked, remove the bacon from the pan and place on a paper towel-lined plate. Once cooled, chop the bacon.
In the same pan used for cooking bacon, remove most of the grease, leaving behind a little to add flavour. Melt the butter over medium heat, add the cabbage and scallions and cook until the cabbage is wilted, about 10 minutes.
Once the potatoes are fork-tender, drain them and return them to the same pot. Add the milk to the pot of potatoes and begin mashing them. Add the chopped bacon and cooked cabbage mixture to the pot. Stir until all the ingredients are evenly incorporated.
Season with salt, pepper and chives.
