I'm traveling to Cusco in August. On my way back to the U.S. I have about a 6 hour layover in Lima in the evening. I'm looking for a spectacular restaurant that isn't formal & stiff. Huaca Pucllana sounds like a good bet.
Depends on what you want. Six hours is not a long time considering the effort to get in & out of security at the Lima airport.
But if you can, take a taxi to the Larcomar shopping center in the Miraflores neighborhood of Lima. (It's on the coast, and the center is directly across the street from the Marriott hotel.) Stop in at the Matsuhita restaurant for sushi & Japanese dishes.
Matsuhita is the first restaurant that a well-known Japanese sushi chef opened on his own, and the name is his. When he went on to open more spots in the US he also named them after himself, but used his surname instead ... Nobu.