Begin by peeling and chopping your russet or Yukon Gold potatoes into evenly sized chunks, ensuring they cook uniformly. Place them in a large pot, covering them with cold, salted water. Bring the pot to a boil over medium-high heat, then reduce to a simmer, cooking for about 15-20 minutes until fork-tender.

Once the potatoes are tender, carefully drain them in a colander and return them to the pot. Add in the creamy butter and mash the potatoes using a potato masher until smooth, yet fluffy.

Stir in the grated carrots, sweet corn, and shredded cheddar cheese into the mashed potatoes. Mix thoroughly, allowing the heat from the potatoes to melt the cheese slightly for a deliciously creamy result. Season to taste with salt and pepper.

Transfer the Cowboy Mashed Potatoes into a warm serving dish, and sprinkle additional cheese on top if desired. Serve immediately for a comforting side.