AMT Gastronorm 2/3 - 2cm with perforated BBQ surface-handles

A: Air underneath. In a convection or combi oven the perforations let hot air reach the underside of the food instead of it sitting on a sealed surface, so it crisps rather than steams.

A: It is bought mainly for combi and convection use, yes. In a static oven or on a hob the perforations do far less, and the plain ridged version is the better buy.

A: Through the pan. That is the trade: perforation gives airflow and drainage, and it gives up the ability to contain what drains. It needs a solid pan or tray beneath it.

A: Yes. Perforated pan above, solid GN pan below to catch. Both are standard fractions, so they sit together in the same racking without anything custom.

A: Fat reaches the oven floor and burns off there. That is a cleaning problem and, in a busy oven, a smoke problem. It is worth stating plainly at the point of sale.

A: Comparably on the ridges themselves. The difference shows in the finish rather than the marking: drier, crisper, less of the food sitting in its own liquid.

A: Anything that will pass through the holes, and anything that should keep its own moisture. Perforation is there to dry and drain, so a dish that needs its juices is in the wrong pan.

A: Slightly. Ridges and perforations both need attention, and residue can lodge where the two meet. A soak and a soft brush handles it; abrasives do not.

A: Combi oven users, effectively only. Hotels, contract catering and production kitchens with combis buy it as a matter of course; a customer without one has no use for the perforation.

A: By oven type. Combi buys perforated, gas and hob buy the handled solid version, induction lines buy the induction one. The equipment decides, not the menu.