It's a $5-10 knife made of soft stainless steel. Any sharpening solution will cost much more. Start by buying a better knife.
I don't think Chef Ming Tsai even uses these, it was just a quick $ endorsement. I can see it being useful as a cheese knife. His actual rotation is kyocera ceramic knives, a variety of Japanese knives, and chinese cleavers. Source: I watch his show a lot, met him in person, and I know the sous chef at his new casual eatery.
My kids gave me one last Christmas. Sweet gift but at first all I could think was "why, why, why?" Believe it or not I actually use it fairly often. It has its place... very different from when one would use most other knives (unless that is all one has and it meets the need). Sharpening isn't intended, I think.
And I'm quite sure Millions is correct about Tsai. I saw him use it on an infomercial and, if I read the look on his face correctly, even he wasn't totally convinced. The number of celebrity chef endorsements on the infomercial channel is astounding, but I wonder why someone like him would endorse a product like that. I probably don't fully understand the size of that specific market share, or the amount of money that can be made filling that niche.
I got to see and "use" one at the family vacation house which I share as an inheritance with my brothers. First personal claim: I'm not to blame for it coming over there. That caveat is now out of the way.
Kelly Ball, the fast answer is you can't sharpen them. The edge (if I recall correctly) is a two-sided serration and isn't really an edge. What it really is can be described as a mini-saw. The "edge" is wide enough so that It even produces a "kerf". It's something which, for any practical description, will rip the (expletive deleted) out of the food. And there's no way to sharpen those small teeth.
The basic shape of the blade is that of a cheese knife, but this example is really something which I would be ashamed to even describe as "bad cutlery". Somewhere in Hades, there MIGHT be a lowest level of sheer abomination for this type of ugggghhhh, but I strongly doubt it.
I think this must have been put together by someone who followed the maxim about a fool and his money.
Bottom line - I don't like it. Three thumbs down in a two-thumb review.