4 1/2 pounds Yukon Gold potatoes
2 1/2 cups grated mild Cheddar cheese (or Colby, or Red Leicester, if your grocery store sells either of them)
1 cup whole milk
Salt and pepper, to taste
If you have a ricer, use it to mash the potatoes, Otherwise, peel potatoes, cut them in half, and drop them in a large saucepan of cold water.
Put the potatoes on a high heat, and when the water comes to a boil, salt them and turn down the heat to keep things at a resolute simmer for approximately 40 minutes, until the potatoes are tender and feel ready to be mashed when pierced with a fork.
Carefully drain the potatoes, and pour the milk into the emptied-out but still hot pan.
Let the milk warm up, putting the pan over a low heat if need be.
If using a ricer, turn off the heat and mash the potatoes with ricer over the pan and directly into the milk. You may need to use the point of a sharp knife to help you remove the potato skins from the ricer.
Otherwise, simply put the peeled and cooked potatoes with the milk in the pan and mash by hand.
When all the potatoes have been mashed, put the pan over a low to medium heat and beat well with a wooden spoon until hot again.
Add the grated cheese in 2 batches, beating well with your wooden spoon in between each addition.
Season to taste, and serve piping hot.