This pasta dish is a riff on one we learned from home cook Eleonora Fratini Martini in the Marche region of Italy. She transformed canned tomatoes into a complexly salty, umami-rich sauce using anchovies, tuna and tons of olives. Like Martini, we use green olives; they are firmer and more buttery than black ones and give the sauce a meaty quality. We found that olive oil–packed tuna—plus a splash of its packing oil in place of the anchovies—yielded our desired level of brininess. Be sure to avoid tuna packed in water. It lacks the flavor and richness of oil-packed tuna and has a drier, mealier texture. Also, look for tuna with no added salt, which will give you better control over the salinity of the finished dish.