I love how easy and fast this is! And in these times of crisis, it can be made with long-lived pantry ingredients. So it is a self-quarantine specialty. It comes from the 'fuzz's friend Emily.
While your pasta water is heating, sauté in olive oil one finely chopped onion and one finely chopped clove of garlic and one 2-oz can of anchovies until the onions are very soft. The anchovies will dissolve in this process. Add one 6-ish-oz can of tomato paste and as much red-pepper flakes as you can stand, and maybe a bit of salt (the anchovies already provide some salt). Simmer this mess while half of a one-pound package of pasta cooks (preferably spaghetti, says the 'fuzz). When the pasta is done (don't over-cook it), mix the very thick sauce with one cup of pasta water and the pasta itself.
Serves four. If it isn't the end times, garnish with lots of chopped parsley. Variation: Cook without the hot flakes and add them to the garnish. That's good if you have some guests who don't like it hot.
Update: This post supersedes this slower and slightly more boring version of this dish.