So, I had bought a ready meal (I have broken hand) enchilada, something I've never tried before. Instructions says 15 mins at 200c with plastic film lid, then take plastic film lid off and a further 15 mins at 200c. It came in a plastic tray. I never trust plastic so I took them out and put in some foil in a baking tray and that was big mistake as the underside fused to the foil. I got a mushy mess.
I have a silicone baking mat which I have never used. It says heat safe up to 250c on side of box. It seems ideal but I've yet to try it.