Fava Bean, Leek, and Fennel Frittata with Kafalograviera Cheese

Yep, you read that right, kefalograviera is a Greek cheese, similar to aged ricotta or asiago.  It's a sheep milk cheese.  For Greek Easter my cousin went to the Greek market in So. San Francisco and called me to ask if there was anything I needed and I asked for a hunk of this [...]