2 medium cucumbers (about 1 lb.), peeled, halved lengthwise, seeded, and diced
2 cups seeded and diced watermelon
¼ cup minced red onion
2 tablespoons minced fresh cilantro or mint leaves
salt
Instructions
Combine the vinegar, sugar, and hot red pepper flakes in a small bowl. Let stand, stirring occasionally, until the sugar dissolves, about 10 minutes.
Place the cucumbers, watermelon, onion, and cilantro in a large bowl. Drizzle the dressing over the salsa and toss to coat. Add salt to taste. Refrigerate for 1 hour, tossing once or twice, to allow the flavors to develop.
This salsa can be refrigerated in an airtight container for several days.