Even simpler: Panasonic and Amana each sell a commercial microwave oven that has one knob – and that's it. Turn the knob to the time you want to cook, and it st

Even simpler: Panasonic and Amana each sell a commercial microwave oven that has one knob – and that's it. Turn the knob to the time you want to cook, and it starts cooking – on "high", its only power setting. Open the door, and it stops and cancels the timer.