Cut pork roast into 1 inch cubes and place into slow cooker. Pour Yucatán sauce and water over pork, close lid and cook for 4 hours. Once pork is tender, use two large forks to pull apart the meat. Leave pork in slow cooker until sandwich assembly.\nIn a small bowl, whisk together sour cream, lime juice, salt and chopped cilantro. Keep chilled until sandwich assembly. In another small bowl, whisk together kewpie mayo, lime juice, salt and 1 Tbsp of Yucatán sauce. Add cabbage and carrots and mix together until fully incorporated. Keep chilled until sandwich assembly.\nOnce ready to build the sandwich, heat a large sauté pan to medium heat and add 1 tsp of butter to the pan. While the butter is melting, slice each baguette in half lengthwise. When butter begins to sizzle, toast both halves of each baguette.\nPlace a healthy layer of pork on the bottom half of each baguette. Layer slaw on top of pork. Top slaw with pickled red onions and picked cilantro leaves. Smear cilantro crema on top half of the baguette and finish sandwich assembly. Enjoy!