Encounter restaurant is the dome-shaped structure that is synonymous with Los Angeles International airport.
Getting there: LAX is U-shaped. Encounter restaurant is located at the center of the U, surrounded by terminals on three sides. You can walk there from any terminal.
Time estimate: You will need to allow time to get through security and walk through the terminal at LAX. So you will realistically need at least a 2 hour layover for this excursion.