I haven't reheated a meal in a casserole dish in the varoma (I use my microwave) but I have made the steamed bread in a casserole dish so just find a dish that will fit nicely into the varoma bowl, making sure the lid of the varoma will fit on correctly. Cook it on varoma temperature, speed 3 or 4 as Faffa said. Just how long it will take to reheat will depend on how much you have to reheat and will be by trial and error. Start with 10 minutes perhaps then test it and add some more time remembering to reset all buttons once the timer starts singing. In my early days I would forget the temperature button and just press the timer and speed - soon learnt things don't cook too well without constant heat.