Place chuck roast in slow cooker and pour slow cooker sauce on top. Cover and cook on low for 7 to 8 hours, or high for 4 to 5 hours. Shred beef into bite-sized pieces.
Place coleslaw mix, carrots, daikon radish, and red bell pepper in a medium bowl.
In a small bowl, whisk together peanut butter, rice wine vinegar, sugar, soy sauce, ginger, salt, and vegetable oil. Pour over coleslaw mixture and toss to coat. Sprinkle peanuts and cilantro on top.
To assemble, cover bottom of buns with beef and top with slaw.