When I visit Boonville, my preference for restaurants is the Buckhorn, across the street from the Boonville Hotel. It has a full bar, and the food is outstanding. Hamburgers and other sandwiches from $11; entrees from $20.
Buckhorn Boonville, 14081 Highway 128, Boonville; (707) 895-3224, thebuckhornboonville.com. Closed Tuesdays.