In a large bowl, mix the leftover mashed potatoes, green onions, flour, salt, ground black pepper, an egg, and mozzarella cheese.
Scoop up one tablespoon of the mixture. Then, using your hands, form a patty with it. Dip both sides of the pancake into the breadcrumbs, then set aside on a flat surface. Repeat with the remaining mixture.
Heat the oil in a large skillet over medium-high heat. Then place the pancakes in a single layer leaving enough space between them. Sauté for 3 minutes on each side until golden brown. Serve immediately.
Notes
Don't form big sized patties because it’s difficult to flip them.
When cooking the pancakes try to leave a suitable space between them to be able to flip them onto the other side easily.
I highly recommend use a non-stick skillet to cook the potato pancakes.