Does anyone know where that Tapas place is in the Huertas/Sol area of Madrid which just sells pig's ears? I went there once and can't remember where it is exactly

I don't know, but pig's ears is a pretty popular tapa and you can find it in sauce or grilled in many bars or tapas bars.

Ignacio is right

Are you thinking of La Oreja de Oro? I think it is closed. It was across from one of the Abuelo (sweet wine and shrimp) places.

Oreja de Oro is closed on weekdays. They are open from Thursday night until Sunday afternoon.
Try La Zapateria across the street. They have several delicious varieties of "orejas".

AH!! Weekdays only. That would explain why my friend thought it was closed completely.

Oreja de Oro has since closed permanently, even though they are featured prominently on the latest Rick Steves visit to Madrid. The owners wanted to retire.

It was remodled and reopened with the same name under the management of El Abuelo. They still have (almost) the same menu.

Ummhhh La Zapateria is a very good option, I would vote for Las Bravas too. But please neophyte!, be aware that pig's ears though pretty discouraging by name turn out to be very similar to bacon if only tastier and tenderer. Give them a try, we are dealing with very addictive material here!

Since Oreja de Oro reopened, their old cook Jaime has opened his own place called "Oreja de Jaime" just a few feet away on Calle de la Cruz.

He has all the old menu items from 'Oro' and also of course Jaime himself.