In the Vitamix container add bananas, orange, and mango. Add 1 tablespoon of agave nectar. Then, using approximately 2 full heads of washed dark green Romaine lettuce, stuff and pack lettuce leaves on top of the fruit until they reach the MAX FILL line on the container. Then, fill the container with purified water to the MAX FILL line. Add a pinch of Celtic Sea Salt.
Cover and blend for 20 seconds until smooth. Serve immediately. Smoothie keeps for a few days in the refrigerator.