Preheat oven to 400°F and fill a medium bowl with cold water. Set aside.
Chop the ends off of your potatoes. Then, cut them in half lengthwise. Cut each half again, reserving the inner 2 slices in the bowl of cold water and disregarding the outer, rounded parts.
Working with one slice at a time, place a skewer on either of the long sides. This will act as a guard so you don't cut all the way through the potato.
Working from one end to the other, slice vertically and tightly (about 1/16 inch slices).
Then, flip the potato over and cut in the same fashion, but at a 45° angle.
To insert skewer, press potato down with the palm of your hand and push wooden skewer directly though the center. Make sure enough of the skewer pokes out at the other end so you can fan out the potato. It's ok if you fuck this part up, I do it all the time. Just improvise and, whatever you do, don't stress!
Pick the skewered potato up and pull the ends of the potato in opposite directions in a twisty motion that resembles DNA. BE CAREFUL, THEY'RE FRAGILÉ!
Place your skewered and fanned accordion potato back in water and take out the next one to work with, repeating above steps.
Once all potatoes are accordionized, line a baking sheet with parchment paper.
Take potatoes out of water, brush each side with olive oil, and season both sides well with salt and pepper.
Bake for 50 minutes, flipping gently halfway through, or until they've reached the sensual brownness you desire.
While potatoes are baking, grill corn over a medium to medium-high flame. I legit place mine directly over the flame on my gas stove. Use tongs to rotate and move. Should take a few minutes on each side to achieve a good char.
Once cool enough to handle, remove kernels with a knife, place them in a bowl, and set aside.
Next, combine sour cream and mayo.
When potatoes are done baking, carefully remove skewers. Then, drizzle them generously with sour cream/mayo crema, sprinkle roasted kernels all over, douse in cotija, and garnish with cilantro.
Serve with lime wedges so people can squeeze the moist juices out themselves.
ENJOY! YAY!