Preheat your oven to 375°F (190°C).
In a large mixing bowl, combine the boiling water and scalloped potato mix seasoning packet.
Stir in the milk, shredded cheddar cheese, and sour cream until well blended.
Add the sliced potatoes from the mix and stir until evenly coated.
Transfer the mixture to a greased baking dish.
Sprinkle cooked bacon bits on top and season with salt and pepper as desired.
Bake in the preheated oven for 25-30 minutes, or until the potatoes are tender and the top is golden and bubbly.
Let it cool slightly before serving.