Excerpted from One Good Dish by David Tanis (Artisan Books). Copyright © 2013. Photographs by Gentl & Hyers.
Step 1: In batches, puree the watermelon in a blender, adding a little cold water if necessary.
Step 2: Pour the watermelon puree into a pitcher, add the lime juice and sugar, and stir. Taste and adjust the sweet-and-sour balance.
Step 3: Thin with more cold water if you wish, and refrigerate until chilled or keep on ice.