Watermelon Cosmo - cooking recipe

Ingredients

3 fluid ounces vodka
1/2 fluid ounce triple sec
1/2 lemon, juice of
4 ounces watermelon juice (directions below)

Preparation

To make watermelon juice: In a blender, whiz 1/4 of a whole watermelon cut into chunks, then strain liquid through a sieve, discarding pulp, for watermelon juice.
To make cosmo: Pour all ingredients into a cocktail shaker filled with ice and shake vigorously.
Strain into 2 large chilled martini glasses.
Garnish with a green melon ball, if you like.