In a large mixing bowl, blend together the leftover creamy mashed potatoes, sharp cheddar cheese, garlic powder, sea salt, and freshly cracked pepper until well combined. This will be your flavorful croquette filling.

With clean hands, form the potato mixture into small balls, about 1-inch in diameter. Roll each ball in flour to coat lightly, dip them in beaten eggs, and then roll them in panko crumbs for that irresistible crunch.

In a deep skillet, heat vegetable oil over medium heat. You want the oil hot enough to fry but not so hot that it smokes. Test by dropping in a small piece of the mixture; it should sizzle.

Carefully place the croquettes into the hot oil in batches. Fry them until golden brown on all sides, which usually takes about 3-4 minutes. Keep an eye on their color for that perfect golden hue!

Once fried, use a slotted spoon to remove the croquettes and let them drain on paper towels. This step ensures they're crispy and not greasy.

Present your Cheese-Stuffed Potato Croquettes warm with ranch dressing and barbecue sauce on the side for dipping. Enjoy each crunchy bite!