Stuffing mixture:
Japanese panko bread crumbs
sea salt
freshly ground black pepper
fresh rosemary (remove leaves from stems)
fresh thyme (remove leaves from stems)
minced garlic (fresh or jarred is OK)
grated or shredded mozzarella cheese
shredded pancetta (vegetarians omit)
diced water chestnuts or jicama
melted butter
Mix bread crumbs, seasonings, cheese and pancetta in mixing bowl (I’m not giving amounts because I don’t use a recipe). Add melted butter until sufficiently moist that stuffings will remain in a ball when squeezed by hand. Remove stems and gills from washed mushroom caps. Mound stuffing into caps (don’t just level the caps, pile ‘em high), compressing stuffing slightly (too much and they’ll be tough). Coat a baking dish with olive oil or leftover melted butter. Place stuffed caps in baking dish as close together as possible. Cover with additional shredded mozzarella. Bake at 375 degrees until cheese is bubbly and just starts to brown. Remove, using knife, spatula or pizza cutter to separate individual caps. Be careful to not eat until cooled below tempature of melted lava.
I also like to prepare this using large caps that fill or almost fill the individual “holes” on a muffin pan. Using a muffin pan will eliminate the need to separate the caps. You can also use large mushrooms or portabello mushrooms to fill individual size gratin dishes, soup crocks, or souffle pans for a nice presentation.
Another variant can replace the rosemary and thyme with fresh basil and oregano for a more Italian taste. Bacon may also be substituted for the pancetta.