If you can find the Italian jars of tuna packed in oil, use them–they’re really tasty. Use the drained oil from the tuna as part of the amount of olive oil called for in the recipe.
1 lb dried fettuccini, spaghetti or linguine
1/2 c extra virgin olive oil
2 large garlic cloves, or more to taste, finely minced
generous pinch hot red pepper flakes
2 6-ounce cans tuna packed in olive oil, drained
salt, to taste
1 bunch arugula or spinach, washed, drained and stemmed, if desired
1. Bring a large pot of well-salted water to a boil over high heat. Add the pasta and cook until al dente.
2. While pasta cooks, heat olive oil in a large skillet on medium-low heat. Add the garlic and hot pepper flakes and cook until garlic is fragrant and sizzling. Add tuna and shred it into fine flakes with a fork. Season with salt. Keep warm over low heat.
3. Just before the pasta is ready, set aside 1 cup of pasta water. Drain pasta and return it to the warm pot set over moderate heat. Depending on the size of your pot and skillet, either add the arugula and the tuna mixture to the pasta in the pasta pot, or add the drained pasta to the skillet with the tuna mixture. Then add the arugula or spinach. Toss vigorously with tongs, moistening with some of the reserved pasta water. The greens will wilt in the heat of the pasta. Divide among warm bowls and serve immediately.