Thinly slice potatoes and sweet potato so they are slightly thicker than potato chips. (Note: use a mandolin or food processor for uniform thiness).
Cut onion in half length-wise and slice into thin, half moons.
Preheat oven to 425º F.
In a non-stick skillet, saute onions in a small amount of olive oil over medium heat until caramelized. Remove onions from skillet and set aside.
Add 1-2 teaspoons of olive oil to skillet and heat over medium before adding potatoes.
Starting in the middle of the skillet, spiral potato slices, overlapping about 1/2 slice so it covers entire bottom of skillet. Neatly spiral a second layer of potato slices. Spiral a third row of potato slices around the perimeter of the skillet (this is necessary to keep the thickness uniform as the outside comes up thinner than the center).
Spread onions evenly on the potatoes.
Spiral the sweet potatoes in one or two layers, depending on the size of the sweet potato and the skillet.
Spread Cougar Gold Cheese evenly on sweet potatoes.
Repeat spiraling of potatoes except in reverse: start with outside row and then work your way in with the last two layers of potatoes
Note: After completing the first potato layers, sweet potato layer and final potato layer, press firmly on the center to make sure all the potatoes on the bottom get maximum hot skillet contact.
By the time you have finished, the bottom layer of potatoes should be brown and crisp. I spray a plate slightly smaller than the skillet with cooking spray, place the plate upside down on the potatoes and turn the skillet over, holding onto the plate. Then, I slide the potatoes back into the skillet, browned side up.
Turn off the heat, turn the plate upside down and press firmly onto potatoes. Salt and pepper to taste.
Place potatoes in heated oven and cook for about 20 minutes, or until potatoes are tender (Note: You do not want any crunchiness or raw taste to the potatoes so cook thoroughly).
Remove potatoes from the skillet onto a cutting board. Cut into wedges and serve hot.
Ideal side for breakfast with eggs and goes great with hamburger steak or chicken fried steak.