Meanwhile, clean and scrub the sweet potato well under running water, then dry well with a paper towel.
Using a very sharp knife, cut sweet potato in even, lengthwise slices that are about ¼ inch thick. (Each large, sweet potato should yield 4 to 6 slices) Place slices in a bowl and toss with olive oil. Line a baking tray with parchment paper and arrange slices, being careful not to crowd them too much. Place the tray in the oven and bake for 15 minutes, then remove from oven, flip the slices, and bake again for 10 minutes.
Let cool and stack your Japanese sweet potato with cheese, fried or scrambled egg, avocado, leeks and nuts. Or chose your own toppings! (I made my “toasts” the night before and the next morning heated them up with the cheese for 10 minutes at 400 degrees.) Then added the rest of the ingredients.
