Step 1

We prefer spaghetti or linguine for this dish, but short or tubular shapes such as penne, fusilli, farfalle, ziti, or rigatoni also work. Likewise, we prefer oil-packed tuna, but if you happen to have water-packed tuna instead, don't let that stop you. For a spicier dish, use the full ½ teaspoon of red pepper flakes.

Step 2

Bring 4 quarts water to boil in large pot. While water comes to boil, gently stir tuna, lemon juice, ¼ teaspoon salt, and ¼ teaspoon pepper together in small bowl.

Step 3

Heat 2 tablespoons oil, 1 tablespoon garlic, anchovies, and pepper flakes in saucepan over medium heat, stirring occasionally, until oil sizzles gently and anchovies break down, 1½ to 2 minutes. Stir in tomatoes and their juice and ½ teaspoon salt. Increase heat to high and bring to strong simmer. Adjust heat to maintain gentle simmer and cook, stirring occasionally, until slightly thickened, 6 to 7 minutes. Cover and keep warm over low heat.

Step 4

Add spaghetti and 1 tablespoon salt to boiling water. Cook, stirring often, until barely al dente. Reserve ½ cup cooking water. Drain pasta and return it to pot. Off heat, add tomato mixture, remaining ¼ teaspoon salt, remaining ¼ teaspoon pepper, and remaining 1½ teaspoons garlic and toss until pasta is well coated. Add tuna mixture and toss gently. Cover and set aside for 3 minutes so flavors can meld and pasta can finish cooking.

Step 5

Adjust consistency of sauce with reserved cooking water as needed. Add ¼ cup parsley and remaining 2 tablespoons oil and toss to combine. Season with salt and pepper to taste. Distribute among pasta bowls. Drizzle each portion with extra oil, if using. Sprinkle with remaining 2 tablespoons parsley and serve.