Complex sentence: Foulois found that the Adlon Hotel bar in Berlin was frequented by many aviation cognoscenti, and with food and Allied whisky, Foulois was able to obtain a large amount of aviation intelligence from German pilots which included Hermann Goering.
Split into simpler sentences: Foulois found that the Adlon Hotel bar in Berlin was frequented by many aviation cognoscenti. By sharing food and Allied whisky, Foulois was able to obtain a large amount of aviation intelligence from German pilots who included Hermann Goering.