I got this idea from a recipe in a book I like called Simple Cooking. If you look for it, try to get an edition with nice, big pictures. They were in the one got from the library, but not the one I got from Amazon. It uses the idea of vegetable juices and purees in many of the recipes. The first four chapters are "Building Blocks": Juices, Vinaigrettes, Flavored Oils, and Vegetable Broths.
The recipe I was loosely following was "Whiting with Endive Broth". The dish consists of fish (whitefish in the book, cod here) with endive puree and juice. The tartness of the endive goes well with the delicate flavor of the fish.