Crock pot query

Is it possible to cook a casserole in a casserole dish inside a crock pot?
I want to be able to lift the casserole dish out and freeze it when it is cooked, without the messy crock pot to clean.

Have heard of cooking in an oven bag inside the crockpot. Just leave an air gap when tying the bag. Guess you could cook like you have described. I have cooked a steam pudding in water in a bowl in the crockpot with no problems.

I often cook for 2 in the slow cooker, put a jam jar ring in the bottom of cooker bowl sit a small oven proof bowl with meal in it on it to let heat circulate. If cooker bowl is ceramic add about inch water in bottom, i now have a new searing one that has a metal inner so dont add water to it. Allow a bit more time if doing like this. Or as asue says throw everything in a oven bag, havent tried it but seen some do a casserole in one bag and rice in another side by side and it works.

Thanks so much for your replies. I will give it a go