In a large bowl, stir together the mashed potatoes, cheese, Zestive Seasoning, egg and 3T flour until combined. Using your hands, divide the mixture into 12 portions. Roll each portion into a compact ball then flatten it into a pancake about a 1/2-inch-thick. Place the remaining 1/2 C of flour in a shallow dish and carefully dredge each pancake in the flour. Heat 3/4 of vegetable oil in a large pan over medium heat. Fry the pancakes, in batches, until they're golden brown and crispy on both sides, 3-4 minutes. Transfer the pancakes to a paper towel-lined plate and immediately sprinkle them with salt. Top with sour cream. Serve and enjoy!