It has its own Wikipedia entry: "The Nut Tree Restaurant was an early pioneer of California cuisine, with fresh fruits and vegetables featured in the recipes." Ronald Reagan visited once. More:

Nut Tree is a mixed-use development in Vacaville, California near the intersection of Interstate 80 and Interstate 505. It opened in 1921 on old U.S. Route 40. It was created by Helen and Ed "Bunny" Power as a small roadside fruit stand, and built near the site of Helen's childhood home ('Harbison House' dating from 1907), which she and her husband purchased from her parents not long after their 1920 marriage.

From an early beginning, a strikingly modern restaurant. Alas:

The Nut Tree ceased operations in 1996 due to financial issues brought about by a family feud that was taken to court. The main Nut Tree buildings were demolished in Fall 2003. The Coffee Tree restaurant across the I-80 freeway, another part of the original Nut Tree holdings, was demolished in late 2005.

Was that this place? Click on.