Preheat oven to 400°F. Line two large sheet pans with parchment paper and set aside. Scrub potatoes to clean debris off skins (or peel). Use a mandolin or a sharp knife to slice potatoes
into 1⁄8”-1⁄4” thick slices. Place potato slices into a large bowl of ice water for at least 30 minutes. Meanwhile, saute bacon slices over medium high heat until crisp and evenly cooked through. Use non-stick cooking spray for crisper bacon. Allow the bacon to cool and then chop into small pieces.
When the potatoes have finished soaking, remove them from the water bath to a clean dishtowel. Pat dry (try to remove as much water as possible from the potato slices). Spray parchment paper on the sheet pans with coconut oil cooking spray. Spread the potato slices in a single layer over the parchment paper. Spray the top side of the potatoes with more cooking spray and sprinkle with sea salt.
Bake for 12 minutes and then flip each potato slice over and bake for another 10-12 minutes. Cook time will vary according to how thick the potato slices are. Look for crispness around the edges and a few speckles of light browning. Larger brown spots will taste bitter, although extra crisp, so be sure to remove potatoes from the oven before they brown too much.
Layer potato “chips” in an oven-safe skillet or baking dish. Sprinkle a bit of crumbled bacon, cheese, tomatoes, bell peppers, and jalapeno over the layer of potatoes. Continue layering potatoes and toppings until your nachos are formed. Return the skillet to the oven and bake for just a few more minutes until the cheese has melted. Top with avocado, green onions, sliced spinach, and sour cream. Serve immediately.