In a large bowl, mix together the leftover mashed potatoes, shredded cheddar cheese, chopped green onions, eggs, salt, and pepper until everything is well combined and creamy.

Scoop small portions of the mixture—about the size of a golf ball—and gently roll them into balls. Feel the texture; it should be slightly sticky but moldable for the perfect puffs.

Roll each ball in the seasoned breadcrumbs until they are fully coated.

In a deep skillet, heat vegetable oil over medium heat, aiming for about 350°F (175°C).

Carefully place the balls into the hot oil in batches, frying them for 3-4 minutes or until they turn a lovely golden brown.

Once golden, use a slotted spoon to remove the puffs, allowing excess oil to drip off, and then place them on paper towels to absorb any remaining oil. Serve warm and enjoy the cheesy goodness!