Bring chicken stock to a boil in a large pot over high heat.
Place the cut up potatoes and garlic cloves in boiling chicken broth. Cook until tender, about 20 minutes.
Drain the broth from the potatoes (I like to use the drained liquid for a soup. So I save it to be used later). After draining, return them to the pot so that you can mash with potato masher (be sure and leave lumps in them).
Add butter, milk and salt. Stir with spoon to blend seasoning. Serve with additional butter and garnish with parsley if you desire.