Your idea of that dish has evolved, and if you're a cook, you can start thinking in different ways about it, maybe even a different way than I think about it.
Now the restaurants have begun to catch up with the wine-making; there are numerous great restaurants in Napa Valley, and it's wonderful because the people are there for just that: great food and great wine.
Let's face it: if you and I have the same capabilities, the same energy, the same staff, if the only thing that's different between you and me is the products we can get, and I can get a better product than you, I'm going to be a better chef.
Once you understand the foundations of cooking - whatever kind you like, whether it's French or Italian or Japanese - you really don't need a cookbook anymore.