Preheat the oven to 350.

If using a fish fillet (like halibut) that is more than ¾ inch thick cut it in half horizontally to get two pieces each about ¾ inches thick.  Combine the panko crumbs, garlic powder, onion powder and oregano in a small bowl.

Place the butter in another small bowl. Lay each piece of fish on a cutting board. Place one ounce of cheese at one end of each piece of fish and roll up the fish around the cheese. Secure the roll with a toothpick.

Dip the rolled fish in the melted butter and then coat it completely in the crumbs. Transfer the fish to a lightly greased baking dish.

Bake for 20-25 minutes or until the fish flakes when tested with a fork. Use a large spatula to transfer the fish and melted cheese to each serving plate and serve immediately.