In a large bowl, mix turkey, dried plum purée, water chestnuts, green onions, fish sauce, garlic, sriracha sauce and salt. Chill for 30 minutes to make it easier to form into balls.
Heat oven to 350°F. Divide meatball mixture into 20 portions. Moisten your fingers with water and gently roll mixture into balls. Place on rimmed baking sheet. Bake meatballs about 15 minutes or until cooked through.
Cut rolls in half horizontally and remove some of the crumb to make room for the filling.
For each sandwich, spread a thin layer of mayonnaise on insides of 1 roll. In bottom half of roll, layer a few slices of jalapeño, 4 meatballs, 4 sprigs cilantro and 2 tablespoons pickles. Cover with top half of roll.
*To make sriracha mayonnaise, stir together 1/2 cup low-fat mayonnaise and 1 teaspoon sriracha sauce. Refrigerate, covered.
**To make carrot and daikon pickles, place 1/2 cup julienned carrots and 1/2 cup julienned daikon in a nonreactive bowl.
In a small saucepan, heat 1/4 cup rice vinegar, 2 tablespoons sugar and 1 teaspoon kosher salt just until sugar dissolves.
Cool to room temperature and pour over carrots and daikon. Let stand at room temperature for 1 hour or refrigerate, covered, overnight. Drain before using.