Add oats, milk and water to a pot and bring to the boil. Once boiling, reduce the heat, cover and simmer until the grains are soft (approximately 5 minutes).
In a small bowl, mix together the sauce ingredients. Thin with a little water if necessary and heat if you prefer.
When the oats are done, pour into a serving bowl and top with caramel sauce. Add a sprinkle of pistachios and a dash of cinnamon to taste.