The grill tray I have for my oven buckles and twists when heated which means if I'm trying to grill food part of it will be raised closer to the top grill element. It results in uneven cooking. I have a wide oven (80cm) so would prefer a wider grill tray but a smaller size will be okay provided it is heavy duty and doesn't buckle and twist like the one I have now. I've looked online but all I can see is the same type that I have now, something like cast iron but with a wire rack would be handy. I want to be able to raise the food off the tray on a wire rack so that the fat can drip off into the tray. Please help me find something suitable :)