Wash your potatoes and place them in a large pot. (you can peel the potatoes if you like but I prefer to leave them on for this recipe.) Fill the pot with water, so the potatoes are completely covered, then bring them to a boil over medium heat.
Boil the potatoes until they are fork-tender, about 20 minutes. Drain the potatoes over a large colander over the sink, and run cold water over them just until they are cool enough to handle.
Now you can allow the potatoes to cool to room temperature, or you can prep the potato salad immediately. Or you can even make the potatoes the day before, and place them in the fridge until you are ready to prep your potato salad. I don't mind using warm potatoes as I always chill my potato salad before serving it!
In a large bowl combine the mayo, sour cream, shredded cheese, sliced green onions, and salt and pepper. Stir to combine.
Cut the cooled potatoes into cubes, roughly 1/2 inch in size. Add the cut potatoes to the mayo mixture and toss to combine, toss until all the potatoes are completely coated in the mayo. Be sure to mix gently to avoid crushing the potato pieces.
Taste and adjust the seasoning if needed. Cover the potato salad with plastic wrap or transfer it to an airtight container, and place it in the fridge. Allow the potato salad to chill for 2-4 hours or until you are ready to serve it.
Enjoy!