This was inspired by the Vita-Mix man at my local Costco. He was throwing all kind of stuff in his super-duper blender. He was right: my puny blender can't completely puree citrus membranes, but this still tastes good.
- Cut the peel and pith off the grapefruit, remove any seeds, and chop coarsely.
- Peel the orange, remove any seeds or interior stringy stuff, and chop coarsely.
- Peel the bananas.
- Throw it all in the blender and puree.