This recipe is one of Judith Jones' meals for one.
Peel fingerlings; cut lengthwise into quarters. Cut zucchini in half lengthwise, then into 1 1/2-inch pieces. Toss potatoes and zucchini in rest of oil and season lightly with salt and pepper (about 1/8 teaspoon of each). Spread vegetables in the bottom of a baking dish big enough to hold bass.
Fill cavity of fish with scallions and chopped herbs. Lay fish on top of vegetables, and sprinkle with lemon juice and a little salt. Add sprigs of herbs (if using); bake 30 to 35 minutes, or until flesh is opaque. Transfer whole fish with vegetables to a plate.
Editor's Note: You're bound to have leftover fish. Save about 3/4 cup to make fish cakes later on in the week.
Adapted from The Pleasures of Cooking for One, by Judith Jones, copyright © 2009, with permission from the publisher, Alfred A. Knopf, a division of Random House, Inc.