• 1 seedless English cucumber
• 1/2 miniature seedless watermelon, cut in hunks, a few pretty little dices reserved for garnish
• Several fresh mint leaves, a few reserved for garnish
• Juice of 2-3 fresh limes
• Kosher salt and fruit vinegar, to taste
• Drizzle of olive oil, for serving
Pulse the cucumber in a food processor fitted with the metal blade until finely chopped. Transfer to a large bowl. Add the watermelon hunks and several fresh mint leaves (to taste) to the machine and purée. Pour into the bowl with the cucumber. (Alternately, you can process the cucumber and the melon together.)
Start adding lime juice until the flavor seems about right. Do the same with the fruit vinegar, and the salt. (You can always add more salt later while serving.)
Refrigerate overnight. To serve, place in bowls and drizzle with a little olive oil. Garnish with diced watermelon and reserved mint leaves, if desired.
Store leftover soup, covered, in the refrigerator for up to 3 days.