A little of this, a little of that: Puttanesca!
Just about every time I make a pasta sauce without a recipe, it turns into some form of puttanesca. I can't seem to help it. Some nights it's a little chunkier, other nights a little smoother. An extra shake or two of the jar of crushed red-pepper flakes, and it's spicier. With green olives and basil, it's a touch lighter and more herbaceous. With oil-cured olives and parsley, a bit earthier.
That's the beautiful thing about back-pocket pasta dishes: You can return to them time and again, and make them your own.
I think of puttanesca as Italy's ultimate simple, pantry-friendly sauce. The name famously refers to prostitutes, with stories (most of them seemingly debunked by historians) attributing the connection to the fact that the dish was quick to make between clients - or so aromatic that it helped prostitutes attract them.
The key to making the dish is to have no fear of its pungency and spice. I like to throw in half a cup of olives and a quarter-cup of capers,; anything less than a teaspoon of crushed red-pepper flakes, meanwhile, is too timid for my taste. I don't use the traditional anchovy anymore, but I do sometimes add canned beans (garbanzos or cannellini) for their heartiness and protein. They're pantry staples, so in my book they fit the spirit of puttanesca.