Combine the cucumber slices, rice vinegar and pimentos in a small bowl, cover and refrigerate. In a large casserole dish mix together the shredded chicken, cilantro, Korean BBQ Sauce and Sriracha. Place the chicken mixture in the oven at 350º to heat through before serving. Meanwhile heat the tortillas, a few at a time in a lightly oiled skillet. Drain the cucumber mixture, lightly squeeze out the excess liquid. Fill the tortilla with the warmed chicken, top with cucumber and serve.