An apparently good place to eat and collect one's thoughts or go over a complicated court case. At least it is for Judge Fang, in Neal Stephenson's "The Diamond Age."
It is Kentucky Fried Chicken. The reason it is called "The House of the Venerable and Inscrutable Colonel" is fairly understandable.
The setting of the story is China, sometime in the distant future. That being the case, some points of Chinese culture are woven throughout the story. One aspect of Chinese culture is to revere, with respect and appreciation, one's betters or elders. Colonel Sanders, the founder of Kentucky Fried Chicken, is considered to be "venerable" for the sake of his fluffy white goatee, which is "a badge of unimpeachable credibility in Confucian eyes." Clearly, the Colonel is old and wisened, or he would not still be a colonel or have lived so long to have white hair.
Colonel Sanders is attributed the characteristic of being "inscrutable" because he guarded his Secret of Eleven Herbs and Spices so closely, even to his grave. Despite the numerous knock-off businesses that have tried to unravel the mystery of KFC's secret blend of herbs and spices with which their chicken is made, the Colonel has managed, by the book's time-reckoning, to hold fast to his secret. To manage such a feat requires guile, discretion, steadfastness and daring- qualities highly respected in Confucian society (and Judge Fang is a Confucian judge- from Brooklyn, New York).
The House, the Kentucky Fried Chicken, is his, this Venerable and Inscrutable Colonel Sanders.