cooking a roast means you'd have to rely on intra-food conduction to cook the center, and since that sort of conduction takes a long time during which you have to continue pushing heat into the food, the utility of using a microwave in the first place is lost.

I'm glad to see you are not perpetuating the [erroneous] myth that microwave ovens cook "...from the inside out."

But, if a mocrowave oven has to "...rely on intra-food conduction to cook the center...", then what does a conventional oven rely on? Seems to me it heats the outside, just like a microwave oven, and the heat has to migrate towards the center the same way.

Perhaps it is a function of the higher external temperatures provided by a conventional oven?

tanstaafl.