Cook the bacon following my Easy No-Mess Crispy Oven-Baked Bacon recipe. Crumble the bacon, finely shred the cheese, and slice the green onions; set all aside until ready to use.
Place the cubed red potatoes in a large pot, cover them with cold water by about an inch, and add Kosher salt. Bring to a boil over medium-high heat. Reduce the heat slightly and let simmer for 10 to 12 minutes, or until the potatoes are fork-tender but still hold their shape.
Drain the potatoes thoroughly in a colander. Line a half sheet pan with paper towels and place a cooling rack inside the prepared pan. Then spread the potatoes out on the rack and let them cool completely to room temperature.
In a large mixing bowl, whisk together the sour cream, mayonnaise, the package of dry ranch dressing mix, and freshly ground black pepper until smooth and well combined. Add the cooled potatoes to the bowl with the dressing and gently fold with a silicone spatula until evenly coated.
Then add crumbled bacon, shredded cheddar cheese, and sliced green onions to the bowl and gently fold until the everything is evenly coated.
Cover tightly and refrigerate for at least 1 to 2 hours before serving to allow the flavors to fully meld. When ready to serve, transfer to your serving bowl and top with reserved bacon, cheddar cheese, and green onions for a beautiful presentation.