Tater cakes, as I grew up calling them, is a great way to use leftover mashed potatoes. Most recipes call for eggs but my grandma never used them in hers. She just used self rising flour and added until they felt right. Then she formed her cakes and dipped them in flour. Fried in crisco in a cast iron pan until golden. You can add bacon, cheese, chives, or whatever mix ins you want but we ate them plain. They ate good on their own but for some protein you could top with a fried egg.