Heat butter over medium heat in a saucepan.  Add oats.  Cook, stirring frequently, until oats begin to smell toasty, about 2-3 minutes.  Add milk, water, salt and cinnamon and stir to combine (be careful, the liquid may splatter a bit when you pour it in).  Bring the mixture to a boil and then turn off the heat and cover the saucepan.  Let sit for 7 minutes.

Remove the lid and serve with a generous sprinkle of brown sugar, a drizzle of cream and a dash of flaky sea salt over the top.