The first time I prepared a lotus root I sliced it too thickly and attempted to roast it in olive oil, salt & pepper like brussel sprouts. It was not good. Then a co-worker told me about a cold lotus root salad she was able to duplicate from her local Japanese restaurant. She generously shared both the recipe and a lotus root and I was on my way.
For those of you who are unfamiliar, lotus roots look kind of potato-y, but they're much more fun looking inside. They can usually be found in Asian markets. Wash, peel, and slice thinly using a mandoline. Be careful. Bring water to a boil with a pinch of salt. Drop in sliced lotus root, bring to a boil again, and cook for five minutes. While it's cooking, combine all of the other ingredients in a bowl.
When the root slices are cooked but still crisp, drain in a colander, then rinse immediately with cold water.
Pour all ingredients into a ziploc bag and marinate in the fridge for at least two hours, squishing around every half hour or so.
For easy and immediate munching, arrange on a plate and serve with sriracha.
With a little more effort, they would also be great served with rice or on a bed of salad greens.