2. Step
Cut banana in half crosswise; peel 1 banana half and set aside. (Reserve the remaining banana half for another use.) Place the frozen watermelon, peeled banana half, strawberries, yogurt, agave (or honey) and salt in a blender. Process until completely smooth and creamy, about 1 minute, stopping to scrape down sides as needed. Divide between 2 glasses. Garnish with watermelon wedges, if desired.