Shallow-water poached means that it USES very little liquid to cook the fish, so the fish is not under water. This recipe and technique works for any fish, but fish with dense flesh, such as glass barracudas, grouper, snapper or flounder, work best because their muscles are so tightly packed that they retain some bite between teeth when cooked.
The healthy way to cook fish is to cook it just right, then make a quick wok sauce from the fish-flavorful broth that is already in the pan, then saute zucchini or broiled cauliflower.