The long queue at Humphry Slocombe has a silver lining: waiting leaves more time for mulling over what to order at this Mission district hotspot. Should one order a scoop of the top-selling Secret Breakfast, with its much-vaunted combination of bourbon and toasted cornflakes? Or try the red-wine-and-cola Jesus Juice? Or something more conventional, such as Tahitian vanilla or ancho chocolate? (Hint: all of the above!) The small, soda fountain-style Formica bar offers limited seating, under the watchful gaze of a double-headed taxidermy calf.