Put the berries in a saucepan with the oatmeal and milk. Heat everything together and simmer for two minutes. Stir so that the milk does not burn. Add the butter. Pour the heated mass into a container to puree and add the bananas, puree.
In total, about 340 g of porridge come out.
Notes: I keep leftover porridge in the cold. When the porridge cools, it becomes a little firmer. Sometimes I make double the amount, freeze some of it and add it to breakfast with a dollop of yogurt.
I like to cook the berry porridge in winter too, so that there is a little fruit variety. I have a pack of frozen strawberries, raspberries and mixed berries in stock in the freezer.