Tip the frozen blueberries into a saucepan and bring to the boil. Mash them with a fork - or blend them lightly with a stick blender.Put in the fridge and leave to cool.
Put the porridge oats, chia seeds, vanilla sugar, salt, honey, milk and skyr in a bowl along with 140 g of the blueberry compote - save the rest for topping.
Stir well, cover with a lid and chill for at least 2-3 hours, preferably overnight.You can also mix the ingredients in 2-3 serving jars with lids. Make sure there is enough room for the toppings when serving. That makes it easy to take with you on the go, or simply grab a jar in the morning or for a quick lunch.
Stir the oats before serving. Adjust the consistency with a little more milk or yoghurt if you find they have become too firm.*If you have used plain yoghurt, you can also add extra vanilla sugar to taste.
Top the oats with extra vanilla skyr, blueberry compote and a generous sprinkling of granola or other crunchy topping.