Bring a pot of salted water to a boil. Add the pasta and cook according to the package instructions until al dente (firm to the bite).

Before draining the pasta, carefully scoop out about 4 tablespoons of the starchy pasta cooking water and reserve it. Drain the pasta and set it aside.

While the pasta cooks, heat the olive oil in a skillet over low-medium heat. Add the minced garlic (and chili flakes, if using) and sauté for 1 minute until fragrant. Be careful not to burn the garlic.

Add the drained tuna to the skillet. Use a wooden spoon to break it up gently, then cook for 1–2 minutes to warm it through and infuse it with the garlic oil.

Pour in the heavy cream, dried oregano, salt, and black pepper. Stir gently and simmer for 2–3 minutes, until the cream bubbles and thickens slightly.

Add the cooked pasta and the reserved pasta water to the skillet. Toss everything together vigorously for 1 minute. The starchy water will mix with the cream, creating a glossy sauce that coats every noodle.

Taste and adjust the salt if needed. Serve immediately while hot.