Lateral is a good restaurant.
In Madrid you can really get tired of Tapas, you can eat them everywhere.
On my fourth day in Madrid I went to Lateral and, despite being tired of Tapas, tried the ones in there.
It was a good experience, the food was nice (above the average Tapas) and the place is cozy (low lights, nice decoration and a good space outside for eating).
I would recommend Lateral to a couple who's looking for a place for a more romantic dinner .