Combine the oats, milk, sweetener and vanilla in a heavy bottomed pan on a medium heat. Cook for 5 minutes, stirring as you go until combined. Leave to stand for a minute.
To make the blueberry compote, heat the blueberries and lemon juice in a small saucepan on a medium heat for 2 minutes until piping hot.
Add the oats and compote into a bowl and top with a hearty dollop of peanut butter.