I love Iron Chef the series, and I would consider buying this game even if it sucks, because the concept of the game is exciting.
The Person who stated they need to "Rock Band" it.
I actually like your idea, but not adding a Kitchen Stadium, but make it more like a rythme game. Here is what I mean.
Iron Chef is about cooking great gourmet foods quickly and flawlessly and then being judged. Well, you can't just easily translate that into a game, because tasting food is weird.
What you can do though create a game where you are doing simple actions in a correct rythme to finish the dish properly. Messing up will either make the food taste bad or slow you down. The more complicated the dishes the harder and longer it takes to create and therefore the more actions you have to do properly to get it right.
Now, add to that the ability to manage the Suis Chefs and how they are cooking, and then being able to create your own plate designs it could be very fun.
I also like that you can pick from the large menu for each secret ingredient available...perhaps something like 20 different dishes for each secret ingredient.
Also you could attempt flair challenges to make your food better if you have the time, but it would be a big reward/risk proposition...if you make mistakes you can really make your food taste bad.