I posted a bit on this on another thread http://chowhound.chow.com/topics/777393 but thought this dish was so exceptional I wanted to highlight it. I've only read about these before and was stunned and delighted to find them at Julian Serrano - each order contains a generous fistful of spaghetti-diameter eel, sizzling in a cazuela with garlicky olive oil.
I overestimated my tablemates' enthusiasm for admittedly wormlike creatures (that, to be honest, appeared to be squirming in the hot oil as they hit the table) and ate one and half cazuelas worth on my own. The texture was like perfectly cooked fresh pasta, and the flavor was sweet and mild, deeply infused with garlic oil, with just the barest hint of anchovy at the end.
Our server said they had just come in season, and will be available for a few more weeks.