When you only have bananas to work with as far as fruits go, you need to get a little creative in making a smoothie out of them, and banana and peanut butter go well together. :)
3 large bananas
3 dessert spoons plain greek yoghurt
2 tbs raw oats, ground
1/2 tbs smooth peanut butter
1/2 tbs agave nectar
1 cup rice milk
Makes 2 large servings.
Chop bananas, combine everything in a blend and blend until smooth. If you're not already adding flaxseeds to another part of your breakfast (eg muesli), then add 2 tbs ground flaxseeds to the smoothie as well.
You can add more agave if you want to taste it more in the smoothie - I just added a little so that the peanut butter isn't too overwhelming in the smoothie.
Agave nectar is a low GI natural sweetener that can be used in place of sugar and honey, with the added benefit that it's vegan because it's obtained from a plant. It has a really lovely flavour and can be used in the place of syrup as well, such as on pancakes, and is really good for replacing sugar in baking. I'll post some more info on this soon. :)