Pat the chicken thighs dry with paper towels and season lightly with salt and pepper on both sides. In a small bowl, whisk together the BBQ sauce, soy sauce, freshly grated ginger, and red pepper flakes until well combined. This helps distribute the ginger and spices evenly throughout the sauce rather than having them settle at the bottom of the slow cooker.

Add the prepared chicken thighs to your slow cooker in a single layer if possible. Pour the sauce mixture from Step 1 over the chicken, then add the pineapple tidbits with their juice. Stir gently to coat everything, then cover and cook on high for 4.5 to 5 hours, until the chicken is fall-apart tender. I find that checking at the 4.5-hour mark helps prevent overcooking, which can make the chicken dry and stringy.

Remove the cooked chicken to a cutting board or bowl and use two forks to shred it into bite-sized pieces. Return the shredded chicken to the slow cooker and stir it back into the sauce and pineapple. Taste and adjust seasonings if needed. The mixture should be saucy but not swimming in liquid—if it seems too wet, let it simmer uncovered for 10-15 minutes on high to reduce slightly.

Lightly toast the Hawaiian rolls if desired (this helps them hold up to the saucy filling and adds a nice texture). Use a slotted spoon to portion the Hawaiian chicken filling onto each roll, allowing excess sauce to drain back into the slow cooker. I like to spoon a little extra sauce on top of each sandwich for more flavor, but you can also serve it on the side for guests to add as they prefer.