Homegrown ’s blackboard menu has a sweet, summery new addition: a watermelon caprese. This seasonal sandwich is the fourth in a yearlong series of partnerships in which ten percent of sales of a particular ‘wich benefit an organization of Homegrown’s choosing. Solid Ground, Mountains to Sound Greenway, and Seattle Tilth have been past partners. This time, it’s local non-profit City Fruit.

City Fruit mobilizes teams to collect the fruit of neglected trees. The shiniest apples and most perfect plums go to food banks while dinged-up pears get used by local restaurants in jams and sauces. The partnership with City Fruit seemed a natural one, says Homegrown co-founder Ben Friedman—both establishments are into improving the local food system—and a fruit sandwich the natural choice.

Friedman has played with melon before, in a prosciutto-burrata stack, and liked the way it worked as a sandwich component. Surprisingly, the fruit doesn’t make for irreparably soggy bread. The watermelon is dehydrated a bit with salt and patted with towels, leaving just enough moisture (and enough juice for some slight chin-drippage). The whipped, salty feta plays off the sweet melon, while the meaty slices of heirloom tomato give it some heft and savoriness. A dose of balsamic brings it back to earth, and basil completes the caprese with its brightness.

The watermelon caprese is available through September 20 at all three Homegrown locations.