This is as simple and as basic as a recipe could be, and all the better for it. I love the way Italians cook greens with their pasta, and often those are the recipes, perhaps thought to be unglamorous, that don’t make it over here. And maybe it’s also the case that non-Italians need a little more persuasion to throw a lettuce into their saucepan. If you can’t get escarole, which is a member of the endive family, use any similar lettuce — curly endive, frisee, or some such. What you want is a robust leaf with an edge of bitterness, and with it I think you need an equally robust pasta. I always go for the thick rough ribbon of pappardelle, but failing that, you might consider rigatoni.