All Freeze and no Time makes Lasagna a dull dinner

I was only told this recently after using a microwave oven for many years. Works as advertised.

If you have cold spots it's more likely that you didn't stir the dish and/or the rotator tray is busted and/or the magnetron is dying.

Or reduce even more the power (with the equivalent increase in timer) as required.

My oven makes them at 30% power.

I recently learned to use my microwave’s “Reheat” feature and have been getting pretty good results. (I have not tested on bricks of frozen lasagna, though.)

https://www.youtube.com/watch?v=Limpr1L8Pss