Preheat your oven to 375°F (190°C) and grease a cast iron skillet or an ovenproof pan with butter or oil.

In a large mixing bowl, whisk together the eggs, heavy cream, salt, and black pepper until smooth and slightly frothy.

Stir in the cheddar, mozzarella, parmesan, and cream cheese until well combined.

Pour the mixture into the prepared skillet and cook over medium heat for 4-5 minutes until edges begin to set.

Transfer the skillet to the oven and bake for 12-15 minutes until puffed and golden brown.

Let the frittata rest for about 5 minutes, then garnish with fresh herbs if desired.

Slice into wedges and serve warm.