Ingredients

• 1/2 cup thinly sliced red onion
• 1 1/2 cups plain whole-milk Greek yogurt
• 3 tablespoons mixed lemon-scented herb leaves (such as lemon verbena, lemon thyme, lemon balm, or lemon mint), finely chopped, plus more whole leaves, for garnish
• 2 teaspoons honey
• 1 tablespoon plus 2 teaspoons fresh lemon juice, divided
• 2 1/2 teaspoons kosher salt, divided
• 1 (5-pound) yellow or red seedless watermelon, cut into 1-inch cubes (about 8 cups)
• 1 (4 1/4-pound) cantaloupe or other muskmelon, cut into 1-inch cubes (about 6 cups)
• 1 1/2 tablespoons extra-virgin olive oil
• 1 serrano chile, jalapeño, or red Fresno chile, thinly sliced
• 1 1/2  teaspoons Aleppo pepper
• 1 lime