Prepare the garlic and the chili pepper as described above and put them into a cold skillet with the oil and a few parsley stems. Slice the pepper or leave it in one piece, according to your taste;
Cook it for one minute until hot and then remove it from the heat; let cool down. Put the pan over the heat and cook until warm again; let cool down. Repeat this process three times: this operation will allow the garlic and pepper to release their full aroma;
Remove the parsley to prevent any bitter aftertaste in the sauce;
Crush the peeled plum tomatoes with a masher and add them to the skillet when the oil has cooled down;
Cook this mixture over low heat until it boils;
Simmer for about 15 minutes until the sauce thickens. Stir occasionally;
Season with salt to taste;
In the meanwhile, cook the pasta in plenty of salted water;
Drain the pasta al dente and stir into the sauce;
Combine well until pasta is evenly coated;
Sprinkle with freshly chopped parsley;
Serve hot. Enjoy this Italian delicacy, with or without cheese to your taste.