Place the chicken into the slow cooker. Arrange the chicken so there is minimum or no overlapping.
Combine soy sauce, hoisin sauce, Thai sweet chili sauce, honey, garlic, and onion in a bowl. Stir to mix well, and pour evenly over the chicken.
Cook on low. For bone-in breast and thighs, cook for 4 to 5 hours. For boneless breast and thighs, cook for 3 to 4 hours. Once the chicken is done, you can leave it in the cooking liquid before serving, so it will further absorb the flavors.
When you’re ready to serve, transfer chicken to a cutting board and shred into thin strips using two forks.
(Optional) To make the sliders even tastier, you can use cornstarch to thicken the sauce to create a gravy. Drain the cooking liquid over a fine mesh into a small saucepan and discard the solid pieces. Cook until brought to a gentle simmer. Turn to low heat. Mix cornstarch with 3 tablespoons water in a small bowl until completely dissolved. Pour into the sauce and stir immediately to mix well. If the sauce is still not thick enough, you can add a bit more cornstarch slurry until it reaches desired thickness. Remove it from the stove and cover to keep warm.
While the chicken is cooking, combine all the ingredients for the coleslaw in a big bowl and mix well. Cover and store in the fridge until ready to serve.
To assemble the sliders, add a handful of shredded chicken onto the slider bun, top with slaw, drizzle with a spoonful of sauce, garnish with cilantro and sesame seeds (if using). Enjoy!