Nutrition Video: Fresh and Fruity Watermelon Slush Recipe By UPMC, August 31, 2017 This simple slushie looks as vibrant as it tastes. Make it yourself by blending ripe watermelon and freezing your puree overnight. For an extra kick of flavor, we added lime juice, basil, and mint to our version. Watermelon Slush Recipe Cooking Time: 10 Minutes Serving Size: 1 Ingredients Ripe watermelon Lime Mint Basil Instructions Puree watermelon in blender. Pour puree into container. Freeze overnight. Chop with spoon or fork. Add lime juice to frozen puree. Garnish and serve.