Pickle the veggies: In a small pot combine the rice vinegar, water and dash of salt and bring to a boil. Add carrots (if you shredded them, squeeze them out inside paper towels over the sink), cucumber and jalapeño to a large bowl. Pour hot vinegar liquid over the veggies and set aside for 30 minutes.
Make the sauce: Meanwhile, make the sauce and prepare the chicken. In a small bowl combine the mayonnaise, hoisin sauce and sriracha and season with salt and pepper. Set aside, or make ahead and refrigerate.
Cook the chicken: Season the chicken with garlic powder, smoked paprika, cayenne pepper, salt and pepper. Add a little olive oil to a skillet over medium heat. Add the chicken and cook for a few minutes on each side until browned and cooked through. Rest for 5-10 minutes before cutting.
Assemble: Slice the rolls in half lengthwise and toast them, if desired. Spread a thin layer of the mayo sauce on each half of bread. Slice the chicken and place on top. Spoon any leftover sauce on top of the chicken. Drain the veggies and add a big handful to each sandwich. Top with a small handful of fresh cilantro leaves. Sandwich with the top half of the roll and enjoy!