I cut the gills out. Scraping with a spoon seems to discolor the
inside of the cap. Just stand it on its side and cut down through
the gill, rotating the muchroom cap until all is removed. Definitely
a cleaner look. When grilling whole I usually leave the gills in. I do
however drizzle with olive oil, a tiny bit of balsamic, fresh thyme, and
garlic, put in a pan topped with foil and steam them for about ten minutes
in a 400 degree oven, remove, leave covered till cooled. Seams to make
a moister product, especially when you are substituting a portabello cap
for beef in a cheeseburger.