Spaghetti alla carrettiera (“in the style of cart drivers”) is a simple pasta dish easily prepared from the Italian larder. Whereas the Sicilian version is said to be made with garlic, oil, chili, possibly cheese, and finished with breadcrumbs, the Roman version features tomatoes, tuna and dried porcini mushrooms. We used the latter as inspiration for this recipe. But instead of porcini, we cook fresh cremini mushrooms until they are nicely browned, which concentrates and deepens their flavor. White mushrooms work, too, if that’s what’s available. Olive oil–packed tuna is traditional for this dish and the oil often is added to the sauce to enrich it, as we’ve done here.