Begin by making the mint simple syrup. In a small saucepan combine the sugar, water and mint. Bring to a simmer and cook until the sugar is dissolved. Remove from heat and let the mint steep for 15 minutes or until cool.
Remove the mint.
Cut the watermelon from the rind into small chunks. Add the chunks, in batches if it doesn't all fit, into a blender. Blend the fruit until smooth.
Pour through a fine mesh strainer into a bowl.
In a large pitcher combine the strained watermelon juice, lime juice and the mint simple syrup. Place in the refrigerator until needed.
To make a cocktail combine 3 ounces of vodka or tequila in a glass. Cover with ice and fill the glass with the watermelon mixer. Serve with a sprig of mint.
Recipe Courtesy of Megan Mitchell