Preparation Cook pasta in a large pot of boiling salted water, stirring occasionally, until al dente. Drain pasta, reserving 1 cup pasta cooking liquid; return pasta to pot. While pasta cooks, pour tomatoes into a fine-mesh sieve set over a medium bowl. Shake to release as much juice as possible, then let tomatoes drain in sieve, collecting juices in bowl, until ready to use. Heat 1/4 cup oil in a large deep-sided skillet over medium-high. Add capers and cook, swirling pan occasionally, until they burst and are crisp, about 3 minutes. Using a slotted spoon, transfer capers to a paper towel–lined plate, reserving oil in skillet. Combine anchovies, tomato paste, and drained tomatoes in skillet. Cook over medium-high heat, stirring occasionally, until tomatoes begin to caramelize and anchovies start to break down, about 5 minutes. Add collected tomato juices, olives, oregano, and red pepper flakes and bring to a simmer. Cook, stirring occasionally, until sauce is slightly thickened, about 5 minutes. Add pasta, remaining 1/4 cup oil, and 3/4 cup pasta cooking liquid to pan. Cook over medium heat, stirring and adding remaining 1/4 cup pasta cooking liquid to loosen if needed, until sauce is thickened and emulsified, about 2 minutes. Flake tuna into pasta and toss to combine. Divide pasta among plates. Top with fried capers.