Watermelon Margarita

4 cups cubed watermelon (chilled)
1/4 cup fresh lime juice
2/3 cup tequilla
1 1/2 Tablespoon agave nectar, light color
1 1/2 Tablespoon Cointreau
Lime wedges
Combine all ingredients and blend well, ( a stick blender works fine).
Pour over ice and garnish with a lime wedge, and a sprig of mint if you like.
I customize by squeezing an extra wedge of lime for more tartness.
* If Agave nectar is not available you can use simple syrup.