Once TV's devil-may-care ``Galloping Gourmet,'' Kerr got religion some years back and his cookbooks turned austere and preachy. Now he has struck a balance with a principle he calls ``minimax''--designed to minimize risk (from fat and other dietary culprits) and maximize flavor. Many of his own old specialties and those of other chefs have been revamped to fit the principle; new flavor-boosting tricks have been adopted (one recipe ``smokes'' chicken breasts in tea bags); and Kerr calls on Thai, Mexican, and other cuisines for tasty fish dishes that fit the new imperative. Yet there's not only some red meat but some indulgence within the revisions: We find ground-turkey sloppy Joes but chili with beef; some dishes using eggs and some with egg substitutes; de- alcoholized wine throughout but a note that wine with alcohol works just as well; and similar range and contrast in the style department as pheasant with chestnuts, for example, follows catfish poorboys. Overall, though he is working well-trod territory, Kerr does quite well ``minimaxing'' old faves and new attractions, with an upcoming author tour promising max exposure.