Trim any fat from the chicken thighs and cut into 1-inch pieces. Place the chicken in the bottom of a 4-quart slow cooker and top with bell pepper and carrots.
In a small bowl stir together broth, hoisin sauce, soy sauce, brown sugar, garlic, and ginger. Pour sauce over the vegetables and cook on LOW for 3 to 4 hours or until the chicken is cooked through and vegetables are tender.
Whisk the cornstarch with 2 ½ tablespoons of water and stir into the slow cooker along with the cashews. Turn to HIGH, cover, and cook 20 minutes more, or until thickened.
Serve over rice.
