1. Stir hot water, salt, sugar, garlic, chile, peppercorns, and red-pepper flakes together in medium bowl until sugar has almost dissolved. Add cold water. Let cool to room temperature. Pour brine in large, heavy-duty, resealable plastic storage bag. Add pork shoulder. Seal bag and turn pork to coat. Marinate pork in the refrigerator 24 hours, turning bag several times.
2. For the salsa verde, in a blender or food processor bowl combine cilantro, parsley, mint, onion, vinegar, 1 tablespoon warm water, 1 teaspoon capers and 2 cloves garlic. Cover and blend or process, until blended. With machine on, gradually add oil through feed tube, until salsa is smooth. Divide salsa between 2 small bowls. Set aside.
3. Prepare grill according to manufacturer's directions for direct grilling.
4. Drain pork in colander. Discard brine and rinse pork under cold running water. Pat dry. Transfer pork to cutting board and cut into 1-inch pieces. Skewer 4 or 5 pieces of pork on each of 6 skewers. Brush with salsa verde from one bowl; discard any remaining salsa verde in this bowl.
5. Oil grill. Grill kebabs 10 minutes, turning several times until cooked through. Transfer kebabs to large serving plate. Serve with second bowl of salsa verde for dipping sauce. Makes 6 servings.