Oreja de cerdo is a traditional Spanish dish consisting of pigs' ears.  The ears - las orejas - can be cooked in a sauce or simply grilled. 

A la plancha means that a food is grilled on a hot, metal plate.  The preparation of pigs' ears a la plancha is a popular method of cooking this food and is eaten as una tapa- an appetiser.  

First, the ears are boiled then sliced into little pieces.   Next, they are tossed onto the hot, metal base that has a light coating of a green sauce called la salsa Mery.  This prevents the ears from sticking to the base and adds some flavour too.  The sauce is a simple mixture of olive oil, chopped parsley, salt, garlic and lemon juice.