How to bake chips in microwave using grill?

According to Consumer Reports, these microwaves typically have traditional heating elements in addition to microwave heat, or they're combo convection/microwave ovens. The rack is to move food closer to the grill element, or to allow better airflow for convection models.

In that case, you'd use the microwave like a small grill or convection oven rather than a traditional microwave - see the instruction guide for your make and model (typically available on the manufacturer's website.) In this way, you can prepare crispy items like oven-baked tortilla chips or samosas (I prefer oven-baked samosas over fried myself! Mmm.)

The microwave is actually a great tool for making chips of any sort, its ability to quickly dehydrate food is what makes this possible, here is an example of parsley chips:

http://www.youtube.com/watch?v=a8DkQeMxz3E

And here is Nathan Myhrvold making kale chips:

http://www.rachaelrayshow.com/recipe/12945_Nathan_Myhrvold_s_Microwave_Kale_Chips/index.html

The basic idea is to get a thin food that can quickly dry out, spray it with oil, and microwave it.

I have a very powerful microwave (1300W), so in my experience, the plastic wrap usually melts, but you can lower the power if that happens. You can use the grill in your microwave instead of the plastic wrap, the only purpose of the wrap is to make sure that the water in the food can steam out of it without getting trapped next to it.

You can also make puffed grains too, for those, you need to put parcooked grains that have been dried in the microwave, inside a paper back, and spray them with oil. I made crunchy chickpeas this way.