Add the frozen chicken thighs and sprinkle with garlic powder, ginger, sugar, black pepper and salt then add soy sauce and honey and cook on high for 3-4 hours or on low for 5-6. Once cooked remove the chicken thighs from the slow cooker. Pour the reserved liquid through a fine mesh strainer and into a small sauce pot, If you have a lot of fat in your liquid you can spoon some of it off the top before making it into a sauce. In a small bowl, combine water and cornstarch and stir. Mix into sauce and bring to a boil and sauce will thicken. Remove from heat. Serve chicken breast over rice followed by the sauce.