Gem Lettuce Salad With Chamoy Dressing

1 pound baby gem lettuce, washed and dried thoroughly, or two 8-ounce romaine lettuce hearts, cored and leaves separated 1 ripe avocado, sliced 1 mango, peeled, and sliced 1 large watermelon radish or large red radishes, sliced (about 3/4 cup) ¼ cup cilantro leaves

For Dressing:

2 tablespoon apricot or peach preserves ¾ teaspoon chile de arbol powder or 1/4 teaspoon crushed red pepper ¼ cup fresh lime juice 2 tablespoon olive oil ½ teaspoon kosher salt 2 tablespoon finely chopped green onion