the butter in a medium saucepan
over medium heat. Add the oats and toast, while stirring, until they smell nice and nutty, about 3 minutes. Add 3 cups water, the milk
, brown sugar and salt. Turn up the heat, bring to a simmer
and cover. Cook for 20 minutes, stirring occasionally to keep the oats
from sticking to the bottom of the pan. Remove the lid and stir in the banana
. Cover again and cook for 10 more minutes, stirring on occasion, until the oats are soft and creamy. Stir in the berries right before serving.