In a large bowl, combine the cold mashed potatoes, Parmesan cheese, minced garlic, egg, chives (if using), salt, and pepper. Stir until everything is fully combined and smooth.
Scoop out about 1 tablespoon of the mixture and gently roll it between your hands to form small balls. If the mixture is sticky, dust your palms with a little flour or lightly wet your hands. Set the shaped bites on a parchment-lined tray or plate.
Prepare three shallow bowls for coating: One with the flour. One with the beaten eggs. One with the panko breadcrumbs, Italian seasoning, garlic powder, smoked paprika (if using), salt, and pepper mixed together.
Take each potato ball and roll it in the flour, shaking off the excess. Dip it into the egg to coat completely. Roll it in the seasoned breadcrumbs, pressing gently so the coating sticks well.
Pour about 2 inches of vegetable or canola oil into a deep pan or skillet. Heat over medium until the oil reaches 350°F.
Working in small batches, carefully lower a few coated bites into the hot oil. Fry for 3 to 4 minutes, turning occasionally, until they’re crisp and golden brown.
Use a slotted spoon to transfer the bites to a paper towel-lined plate. Let them cool for a couple of minutes before serving.
Serve warm with marinara, garlic aioli, ranch, or your favorite dipping sauce. Enjoy!