Place the chicken in the bottom of your slow cooker. In a medium bowl, whisk together the gochujang, soy sauce, honey (or brown sugar), rice vinegar, grated ginger, minced garlic, sesame oil, and water (or chicken broth) until well combined.

Pour the sauce evenly over the chicken in the slow cooker. Ensure the chicken is mostly covered by the sauce.

Cover the slow cooker and cook on low for 6-8 hours or on high for 3-4 hours, or until the chicken is incredibly tender and easily shredded with a fork.

Once cooked, remove the chicken from the slow cooker and shred it using two forks. Return the shredded chicken to the slow cooker and stir it into the sauce to ensure it's well coated.

While the chicken is cooking or just before serving, prepare the slaw. In a large bowl, combine the shredded green cabbage, julienned cucumber, thinly sliced jalapeño, and chopped fresh cilantro.

In a small bowl, whisk together the lime juice, sugar, and salt until the sugar dissolves. Pour this dressing over the slaw mixture and toss to combine. Let it sit for at least 5-10 minutes for the flavors to meld.

Toast the brioche buns or potato rolls. Assemble the sandwiches by placing a generous portion of the gochujang chicken on the bottom bun, then topping it with a spoonful of the fresh cucumber jalapeño cabbage slaw. Cover with the top bun and serve immediately.