I've lived in Japan, where I took several Japanese vegetarian cooking classes, as well as Spain, so the idea of Japanese-Peruvian fusion sounded interesting. At home, I use Kansha: Celebrating Japan's Vegan and Vegetarian Traditions and Japanese Vegetarian Cooking: From Simple Soups to Sushi as my main go-to books for vegetarian Japanese cuisine (The Enlightened Kitchen: Fresh Vegetable Dishes from the Temples of Japan is also a good reference, especially for its illustrated guide to Japanese ingredients).
I can't say that I've visited any of Nobu's 29 restaurants, but I have looked through some of his other cookbooks (Nobu: The Cookbook, Nobu West). I love some of his unique flavor profiles like azuki-espresso sauce, or exploring the parallels between ceviche and sashimi. So when I finally got my hands on Nobu's Vegetarian Cookbook, I eagerly flipped through it. The book is printed in Japan, and the paper and photography is first-class all the way. However, that's where my enthusiasm slowed. First strike: many of the specified ingredients (finger limes, and most Japanese mushrooms, herbs, fruits and vegetables) are very difficult to find locally, may not be fresh, and are expensive. It's difficult to find acceptable substitutes that won't have an impact on the finished dish, like myoga (ginger buds) or fresh lotus root.
Another hurdle was the prep time involved in the recipes. Despite the fact that Nobu himself says "in most households today I see a trend towards simplifying everyday menus and food preparation that doesn't take a lot of time and effort," this book does just the opposite. For example, the dashi-marinated vegetables have you prepare nine different veggies individually before marinating for 3-5 hours (the prep is the most time-consuming). The causa and tomato chalaquita has you make a four-layered ring mold out of three kinds of potato and pumpkin, each ingredient being peeled, mashed and assembled separately. As another reviewer mentioned, for the vegetable sushi recipes, there is virtually no "how-to," and it's assumed that you already know how to roll sushi (no diagrams, step-by-step, etc.). The glossary is compact but effective.
This is purely subjective, but many of the flavor profiles simply didn't look appealing to me. The biggest offender was texture; I'm really put off by slimy textures, and there are many jelly-type dishes like okra, molokhiya, and yam cocktail, tomatoes with seaweed jelly, ripe tomato in nori and umami jelly, etc.
There are several recipes for vegetable sushi like that pictured on the cover; you will find recipes for box sushi with salt-pressed cucumber, sushi rolls with pickled wild burdock, and finger food like fried kadaif wraps with Maui onion salsa, and party croquettes with brown sauce. There are numerous recipes for vegetable "steaks," like two different recipes for cabbage "steak" (both involving truffles), cactus leaf "steak," onion "steak," etc, and several rice-based dishes (brown rice paella, steamed baby pumpkin and jalapeno rice, arroz con verduras).
The veggie tacos are a great example of fusion(filling options include kimchi, button mushrooms with avocado salsa, pumpkin, zucchini, and bell pepper with wasabi salsa), and the chapter on yuba (soymilk skin) is inspired. Dishes like sashimi yuba tiradito, yuba rolls with black soybean sauce, and seared yuba with avocado dip really shine. (There's a good basic recipe for yuba in Kansha: Celebrating Japan's Vegan and Vegetarian Traditions, but a word of warning: be sure to properly prepare dried yuba, because it needs to be soaked first to soften it).
The desserts lean more towards fusion and less towards traditional sweets; you'll find a bell pepper, coriander, and chicha morada warabi mochi, tomato compote coated with chocolate, candied kabocha pumpkin (candied pumpkin is a Mexican staple; you'll find another excellent version here: My Sweet Mexico: Recipes for Authentic Pastries, Breads, Candies, Beverages, and Frozen Treats), and deep-fried eggplant simmered in sugar syrup and dusted with kinako (toasted soybean powder). Granted, traditional Japanese sweets like wagashi and higashi don't really conform to the Western idea of "dessert" as most are made with rice flour, soybean powder, green tea and/or sweetened bean paste; my favorite nibble in Japan was amanatto (sugared beans).
Overall, this is a gorgeous cookbook to look at, but for everyday use, there are simply too many hard-to-find, expensive ingredients that won't be readily accessible for many home cooks, and many recipes are fairly labor intensive. If you're a fan of Nobu or you enjoy fusion cuisine, then you'll likely enjoy Nobu's Vegetarian Cookbook.