If you're not using a packet mix, how do you make the liquid part of a casserole? Is it just stock? A mixture of tinned tomatoes and stock? And how do I thicken it - do you just mix some flour with cold water and then add that to the liquid, or will it thicken by itself as it reduces? I'm that I don't know this!
I'm planning to make it in a slow cooker if that makes a difference. Thanks!