Place potatoes in pot with water and boil until soft and easy to mash.
While potatoes are boiling, get garlic cloves and rub down with a little oil and place in microwave and cook until soft. When soft and cooled down, remove skins and mash (using a mortar and pestle works great!).
Place milk in small pot with rosemary under a low temperature and allow to cook till milk just starts to bubble a little around the sides, and then turn off heat and allow the rosemary to steep for about ten minutes. Remove rosemary when ready to add milk to potatoes and discard.
When potatoes are soft and mashable, mash with skins on and add in the garlic. Slowly add the warm milk a little at a time, whisking, and adding more until fully incorporated. Add in the butter and seasonings to taste,
Add parsley to garnish and serve.