Wash the mushrooms.

Pat the mushrooms dry with paper towels. Then remove the stem and gills.

Brush olive oil onto the top and bottom of the mushrooms.

Grate the block of mozarella cheese. Please do not use pre-shredded cheese as it sometimes does not melt as well. Set aside.

Now add spoon some pizza sauce onto each of the mushrooms.

Next add a handful of cheese. Do not add too much cheese onto the mushrooms as it can overflow when cooking in the oven.

Lastly top with the pepperoni slices.

Pre-heat oven to 425 degrees.

Brush some olive oil onto the surface of the grill pan.

Transfer the mushrooms to a grill pan or baking dish. If using a baking dish the mushrooms will release some liquid as it cooks in the oven. After it is done cooking in the oven you may want to place the mushrooms on a plate lined with paper towels to soak up some of the liquid to dry the bottoms of the mushrooms.

Place the grill pan in the oven and cook for 20 minutes.

While the mushrooms are baking chop the fresh basil and set aside.

After the mushrooms have baked for 20 minutes, increase the heat to 500 degrees and cook for another 5 minutes.

If the top of the cheese has not browned then you can place the mushrooms under the broiler for 30 seconds to a minute until they have slightly browned. This step is optional.

Remove the mushrooms from the oven and top with the chopped basils.

Serve immediately while warm.