In a large pot, add the water for cooking the pasta, and let it boil. In the meantime, start preparing the sauce.
In a wide, deep pan heat the olive oil. Add minced garlic, chili flakes, and diced parsley stems (save the leaves for later). Cook on medium-high heat for 1-2 minutes.
Add tomatoes, oregano, basil, black pepper, and salt. Stir everything and let the sauce cooks over medium-high heat until thickens a bit.
In the meantime, the water for cooking the pasta started to boil, so add salt and pasta to the pot and cook until it becomes al dente. Strain it, but save a few tablespoons of pasta water (you may need it to finish the sauce).
When the sauce is done, remove the pan from the heat, add freshly chopped parsley leaves and cooked pasta and stir everything together. If the sauce has been reduced a bit too much, add some of the reserved pasta water to it. Try it and season with some salt and pepper if necessary.
Transfer the pasta to plates, and serve with some freshly grated hard cheese on top and a small drizzle of olive oil.