Made this last night... MMM... Anchovies.
It's pasta burro e alici, or pasta with butter and anchovy.
I saw it on Bobby & Giada in Italy, and knew I had to give it a try.
Very simple recipe. Gently melt the butter and anchovy (perhaps with a little boiling pasta water for heat, although you can put the pan over the boiling water as a double boiler to do it gently) until the butter is melted and the anchovies have broken down to become part of the sauce. Add the pasta, and enough extra pasta water to get the sauce smooth and emulsified, and you're done. 4 ingredients.
Definitely a learning experience. The first bowl (pictured) didn't have enough pasta water, which is probably why it looks more buttery than saucy. When I went for seconds, I added some water and suddenly it was completely transformed into this silky delicious amazingness.
Can't wait to try it again. My wife... Not so much. She'd never had anchovy before so she was willing to try this, but wasn't exactly a fan.