Dean's Drive-Inn   Dean's Drive-Inn, like most Isle spots with the drive-in moniker, isn't a drive-in; parking in the little strip mall is the only drawback to eating a weekday lunch here, and there's no drive-through window or car service. But is is owned by a Dean - Dean Mishima, former chef at Liberty House - and the place is as advertised, "Local Boy, Local Food." Grilled 'ahi belly, 'ahi cakes and teriyaki steak are the kind that elicit involuntary murmurs of approval at the table. The desserts taste like those auntie-kine secret recipes you hope will be bequeathed to you someday. One of the best plate lunch places on the island.  Adon Plaza, 45-773 Kamehameha Highway. 247-1300. 11am - 6pm Sundays-Thursdays, 11am - 4pm. Fridays. Cash only. $