What's Cooking? with Jamie Oliver is a great cookbook. Oliver's preferred recipes are heavy on the fresh vegetables, simple ingredients, and easy preparation, and thus even the super-fatty recipes seem sort of healthy as a result. Many of the recipes looked outstanding. And, as a bonus for Chris (who hates Jamie Oliver with a surprising intensity), unlike on the Jamie Oliver TV shows, you don't really have to look at his face or hear his voice that much. You never have to hear his voice, or the game's selection of pleasant elevator music, if you mute the DS!
There were even some advantages to having this cookbook on the DS, as well: you can filter recipes by meat content, preparation time, breakfast/lunch/dinner, and other values, even in combination. You can select recipes and automatically generate shopping lists. Like Cooking Guide, you can control the cookbook's display by voice.
The voice control issue, however, solves a problem that is created by having the thing on the DS anyway: I wouldn't have to view the recipe in so many pieces in a book! It would all just be one page. Then I wouldn't be yelling at it.
As far as the other part of the game, the interactive cooking simulation/game, goes ... it didn't work out. What I thought was a cool idea turned out to be useless at best. As it turns out, learning how to pretend to cook with your stylus doesn't translate to real cooking at all. It's kind of fun to play a completely freeform Cooking Mama, but only for a few minutes. The game doesn't seem to notice when you've completed a recipe, and you don't really learn anything about measurements or proper cooking techniques from holding a carton of milk over the bowl until a green timer elapses or stirring a mixture until the color changes. The completely freeform mode, which allows you to just go into the kitchen and make whatever on your own, seems completely impossible, since you don't know how the game will interpret your recipes. You'll probably end up with a nondescript pile of food.
While developer Keen Games made an admirable effort to simulate cooking, it just isn't helpful in the real world. You'd be better off picking up a Jamie Oliver cookbook and a copy of Cooking Mama for fun. Similarly, the cookbook is nice, but less useful than it would be outside of the DS. Still, it's usable, and you can make food with it.
Final score: 5/10 (pancakes: 8/10)