I used Reynold’s Oven Bags and according to the package, the bag keeps moisture in, resulting in "tender juicy meats." To use the roasting bag, add a tablespoon of all-purpose flour to the bag ...

That is, until we realise that no oven means no roast dinner ... “I’d put a chicken in a roasting bag, lay it in the microwave upside down for 20 minutes and then turn it the other way ...