Place boneless skinless chicken thighs in slow cooker. In a small bowl, combine soy sauce, brown sugar, vinegar, lemon juice, garlic, ginger and pepper then stir until sugar is dissolved.
Pour sauce over chicken in slow cooker. Cover then cook on low for 4 hours.
When ready to serve, transfer chicken from slow cooker to a platter. You may slice, shred or leave the chicken pieces whole. Strain sauce into a medium-sized saucepan.
In a small bowl, stir together cornstarch and water then whisk into sauce. Place pan over medium-high heat then bring to a boil. Let sauce bubble for 1 minute then remove from heat. Pour or spoon sauce over chicken, sprinkle with sliced green onions and serve.
Notes
The long slow-cooking process really absorbs the flavor in the meat—and the chicken is so tender!