In a large 12 inch frying pan cook together butter, olive oil, garlic, and mushrooms over medium-high heat until mushrooms are tender. This should be about 5 minutes. Reduce heat to medium and add in cream cheese and cook until cream cheese has melted. Reduce heat to medium-low and add in parmesan cheese, heavy cream, Italian seasoning, oregano, salt, and pepper. Simmer for 5 minutes, stirring often. Remove from heat and sprinkle with parsley before serving.