In “French Food at Home,” Laura Calder shares a recipe for a simple yet elegant one-skillet, six-ingredient (not counting the salt and pepper) sautéed fish supper. Our riff yields a slightly more substantial vegetable accompaniment to serve with the fillets but is equally easy to prepare. We like green beans, but if you prefer, use pencil-thin asparagus instead. Red snapper is a mild, firm-textured white fish that holds up nicely to sautéing. Flounder is a good alternative, as it typically is of the same thickness as snapper. Halibut works nicely, too, but the fillets are thicker and therefore require a few more minutes in the pan.