Sprinkle chicken with salt and pepper
In a large skillet, heat olive oil over medium-high heat; add chicken and brown about 2 minutes per side
Remove chicken from skillet and place in slow cooker
Mix together soy sauce, apple cider vinegar, honey, garlic, and ginger in a small bowl; pour over chicken
Cover and cook on low 3 - 4 hours
Add in cashews; cover and cook an additional 15 minutes on low
Top with sliced green onions and serve over rice if desired