You certainly can! Slow cooker chicken thighs are a great make-ahead recipe. Simply store them in a freezer-safe bag or container for up to 3 months. Then, when you’re ready, thaw them in the refrigerator overnight and heat them in the slow cooker or oven until heated through. Alternatively, you can skip the searing step and toss the uncooked chicken thighs and sauce in a freezer-safe bag for up to 3 months. Allow it to thaw overnight in the refrigerator and then toss everything in the slow cooker when you’re ready.