Wipe the mushrooms with a damp cloth.

Remove the stems.

Finely grind the stems in a food processor.

Sauté the ground stems in the butter with a pinch of salt until the liquid is drawn out and then completely evaporated.

Mix the cooked stems with the breadcrumbs, eggs, parsley, garlic, oregano, and salt and pepper to taste.

Cool slightly and add 3 tablespoons Parmesan cheese.

Butter a baking dish large enough to hold the mushroom caps in a single layer, snugly.

Fill each mushroom cap with some of the stuffing mixture.

Arrange the stuffed mushroom caps in the buttered dish.

Sprinkle with additional Parmesan cheese, dot with butter and add a small amount of broth or water to the bottom of the dish to keep the mushrooms from sticking.

Bake at 375°F for 20 minutes, until golden brown on top.

Baste occasionally with the liquid in the pan during baking.