Spaghetti alla puttanesca is typically made with tomatoes, olives, anchovies, capers, and garlic. It means, literally, "spaghetti in the style of a prostitute." It is a sloppy dish, the tomatoes and oil making the spaghetti lubricated and slippery. It is the sort of sauce that demands you slurp the noodles Goodfellas style, staining your cheeks with flecks of orange and red. It is very salty and very tangy and altogether very strong; after a small plate, you feel like you've had a visceral and significant experience.
There are varying accounts as to when and how the dish originated- but the most likely explanation is that it became popular in the mid-twentieth century. The first documented mention of it is in Raffaele La Capria's 1961 novel, Ferito a Morte. According to the Italian Pasta Makers Union, spaghetti alla puttanesca was a very popular dish throughout the sixties, but its exact genesis is not quite known. Sandro Petti, a famous Napoli chef and co-owner of Ischian restaurant Rangio Fellone, claims to be its creator. Near closing time one evening, a group of customers sat at one of his tables and demanded to be served a meal. Running low on ingredients, Petti told them he didn't have enough to make anything, but they insisted. They were tired, and they were hungry, and they wanted pasta. "Facci una puttanata qualsiasi!" they cried. "Make any kind of garbage!" The late-night eater is not usually the most discerning. Petti raided the kitchen, finding four tomatoes, two olives, and a jar of capers, the base of the now-famous spaghetti dish; he included it on his menu the next day under the name spaghetti alla puttanesca. Others have their own origin myths. But the most common theory is that it was a quick, satisfying dish that the working girls of Naples could knock up with just a few key ingredients found at the back of the fridge- after a long and unforgiving night.
As with all dishes containing tomatoes, there are lots of variations in technique. Some use a combination of tinned and fresh tomatoes, while others opt for a squirt of puree. Some require specifically cherry or plum tomatoes, while others go for a smooth, premade pasta. Many suggest that a teaspoon of sugar will "open up the flavor," though that has never really worked for me. I prefer fresh, chopped, and very ripe, cooked for a really long time. Tomatoes always take longer to cook than you think they will- I rarely go for anything less than an hour. This will make the sauce stronger, thicker, and less watery. Most recipes include onions, but I prefer to infuse the oil with onions, frying them until brown, then chucking them out. I like a little kick in most things, but especially in pasta, so I usually go for a generous dousing of chili flakes. I crush three or four cloves of garlic into the oil, then add any extras. The classic is olives, anchovies, and capers, though sometimes I add a handful of fresh spinach, which nicely soaks up any excess water- and the strange, metallic taste of cooked spinach adds an interesting extra dimension. The sauce is naturally quite salty, but I like to add a pinch of sea or Himalayan salt, too, which gives it a slightly more buttery taste, as opposed to the sharp, acrid salt of olives and anchovies. I once made this for a vegetarian friend, substituting braised tofu for anchovies. Usually a solid fish replacement, braised tofu is more like tuna than anchovy, so it was a mistake for puttanesca. It gave the dish an unpleasant solidity and heft. You want a fish that slips and melts into the pasta, not one that dominates it.
In terms of garnishing, I go for dried oregano or fresh basil (never fresh oregano or dried basil) and a modest sprinkle of cheese. Oh, and I always use spaghetti. Not fettuccine. Not penne. Not farfalle. Not rigatoni. Not even linguine. Always spaghetti.