This is like the best ham and cheese sandwich you will ever have and that’s all I need to say about it. (But since I am me I will say a little more.) Try to get really good ham if you can find it. Serrano ham is the Spanish equivalent of Prosciutto di Parma, and goes really well with the slightly sharp Manchego cheese. But even if you can only get Prosciutto - or plain old thinly sliced deli ham - you’ll be golden here.