In a blender, combine the water, strawberries, romaine lettuce, lemon- grass, and the ice cubes.
Process just until smooth and then add in the ground flaxseed and pro- tein powder; process again for 5-10 seconds or until well incorporated.
Add additional ice, if needed until desired consistency is achieved.
Pour the green smoothie into tall glass and drink immediately to receive full nutritional value—the nutrients will begin to dissipate the longer the smoothie is exposed to the air.