Each Moment is the Universe is by far among my top-ten favorite zen books. It is a collection of teachings that are shaped by Dogen’s concept of uji (u-ji), which is typically translated as being-time. This is more of a recommendation rather than a discussion of the book’s subject matter — if interested, there is an excellent introduction to being-time from Lion’s Roar available here: Notes on Dogen’s Being-Time by Shoshu Roberts.
One of the things I deeply appreciate about this book is how digestible it is. A chapter can be finished in one sitting and still leave the reader time for reflection. Katagiri manages to use Dogen’s concept of being-time in ways that gave me much to think about concerning both zazen and everyday life.
As digestible as it is, it is also a book that warrants rereading. I look forward to pouring over this text again. If you have an interest in zen literature or the practice of zazen meditation, I highly recommend checking this one out.
You can find a good synopsis from the publisher at this page.