Start by bringing a large stockpot of water to a rolling boil. While waiting, wash the red potatoes thoroughly.

Once the water is boiling, carefully add the potatoes and cook until they are fork-tender. After boiling, drain the potatoes and set them aside to cool in an over-the-sink strainer.​

While the potatoes are cooling, slice the bacon into bite-sized pieces. In a skillet over medium heat, cook the bacon until it reaches your desired level of crispiness.

Remember, the bacon will cook further in the smoker, so slightly undercooking it now is fine. Once done, remove the bacon from the skillet and set aside.​

Once the potatoes have cooled enough to handle, cut them into chunks and place them in a large mixing bowl.

Add the cooked bacon, cubed cheddar cheeses, diced onion, mayonnaise, sour cream, garlic salt, and pepper to the bowl. Stir everything together until well combined.​

Lightly spray your 4.8-quart Pyrex or casserole dish with non-stick cooking spray. Transfer the potato mixture into the prepared dish, spreading it out evenly.​

Preheat your pellet grill or smoker to 250°F (121°C). Once it reaches the desired temperature, place the casserole dish on the grill grates.

Close the lid and smoke the cheesy potatoes for approximately 1 hour and 25 minutes, or until the cheese is melted and bubbly, and the top has a slight golden hue.​

Carefully remove the dish from the smoker and let it rest for a few minutes. Serve the smoked cheesy potatoes warm as a hearty side dish to complement your main course.​