Garlic Parmesan Scalloped Potatoes

butter

minced garlic ((or 4 large garlic cloves, minced))

all-purpose ((or plain) flour)

milk ((skim, 2% or full fat -- more if needed))

chicken bullion powder ((or Kosher salt))

Salt (to taste)

black pepper

Yukon Gold potatoes (or Russets) (peeled and sliced into 1/8-inch - 1/4-inch rounds)

shredded mozzarella cheese

Parmesan cheese ((freshly grated))

fresh chives (divided)