Preheat oven to 350°F (180°C).
Brown ground beef in a large skillet over medium heat. Season with salt and pepper, then let cool slightly.
Blend cream cheese in a food processor and add eggs one at a time until smooth. Stir the mixture into the ground beef. Press into a small 4-cup casserole dish.
Melt butter in the skillet. Cook mushrooms until soft and browned; season with seasoned salt, parsley, and pepper.
Spread mushrooms over the beef mixture. Top with grated cheese if desired.
Bake 20 to 25 minutes, until set. Avoid overbaking.