1. Preheat the oven to 375°F and grease a 9×13-inch baking dish.

2. Heat the butter or oil in a large skillet over medium heat.

3. Add the ground beef, diced onion, and diced bell pepper, then cook until the beef is browned and the vegetables are softened.

4. Drain any excess grease from the skillet.

5. Stir in the cream of mushroom soup, sour cream, garlic powder, onion powder, smoked paprika, salt, and black pepper until the mixture is smooth and creamy.

6. Add the frozen diced potatoes and 1 cup of the cheddar cheese, then mix until everything is evenly coated.

7. Transfer the mixture to the prepared baking dish and spread it into an even layer.

8. Sprinkle the remaining cheddar cheese and the Monterey Jack cheese over the top.

9. Bake for 40 to 45 minutes, or until the casserole is hot, bubbly, and the potatoes are tender.

10. Let it rest for 5 to 10 minutes before serving, then finish with chopped parsley.