Another favorite of mine from www.wwrecipes.com.  What could be better than cheese?  :O)

Cheese-Stuffed Mushroom Caps

1 cup (250 ml) ricotta cheese
1/4 cup (60 ml) finely chopped parsley
1/4 lb (100 g) thinly sliced prosciutto, finely chopped
Salt and freshly ground pepper to taste
1 Tbs (15 ml) fresh lemon juice
4 Tbs (60 ml) olive oil
18 medium-sized mushroom caps
2 oz (50 g) mozzarella cheese, cut into 1/4 in (5 mm) pieces

In a mixing bowl combine the ricotta, parsley, prosciutto, salt, pepper, and the lemon juice and mix until thoroughly combined. Heat the olive oil in a large, heavy skillet over high heat and fry the mushroom caps for about 2 minutes on each side, until lightly browned. Remove from the heat. Fill the mushroom caps with the ricotta mixture and top each with some of the mozzarella pieces. Arrange in a shallow baking dish and bake in the center of a 400F (200C) oven for 8 to 10 minutes, until the filling begins to bubble. Brown the tops under a hot broiler for about 30 seconds. Serve immediately. Serves 4 to 6.