Preheat oven to 425 degrees Fahrenheit (218 degrees Celsius).
In a 10-inch oven-safe skillet, combine thawed hash browns with melted butter, 1/4 teaspoon salt, and 1/8 teaspoon pepper.
Press the potato mixture firmly into the bottom and up the sides of the skillet to form an even crust.
Bake the hash brown crust for 20 minutes until the edges are golden brown and crispy.
Reduce the oven temperature to 375 degrees Fahrenheit (190 degrees Celsius).
In a large mixing bowl, whisk together the eggs, heavy cream, diced bell peppers, onion, and the remaining salt and pepper.
Pour the egg mixture into the pre-baked potato crust and sprinkle the shredded cheddar cheese evenly over the top.
Bake for 15 minutes or until the center is set and the cheese is melted and slightly browned.
Remove from the oven and garnish with fresh parsley.
Allow the frittata to rest for 5 minutes before slicing and serving.