Using a mandolin or your knife skills, slice the potato into thin coins. Take your time here, making sure that the slices are thin, or they will not get crispy in the oven. Once you have the potatoes sliced, place them in a bowl of cold water. Using your hands, swish the potatoes around, being sure to separate the slices so the starch can be released. Dump out the starchy water, and fill the bowl again with fresh cold water. Repeat this step 2-3 more times, or until the water is completely clear, and there is no more starch.
Drain the potatoes, and lay in a single layer on a clean kitchen towel. Lightly pat the coins so they are dry to the touch. Once they are dry, arrange on a baking sheet lined with parchment. Turn your oven to 425F (read your parchment instruction, and make sure is it able to be in ovens at that temperature).
Drizzle olive oil, and toss the coins to lightly coat the potatoes. Arrange the potatoes back into a single layer, and sprinkle with coarse salt and pepper. Place in the oven, and set your timer for 15-20 minutes. After 20 minutes check on your potatoes- they should be browned and crispy. If not, lightly toss again and place back into the oven for another 10-15 minutes, keeping a close eye! Once the potatoes are done, remove from the oven and allow to cool slightly. Sprinkle with more salt if needed!
To make the Jalapeno Mayo, combine the mayo, grilled jalapeño, lime juice and a good pinch of salt and pepper. Stir well to combine- and season with additional juice, salt and pepper as needed.
