Add the pasta and toss with the sauce. Add parsley and 1 tablespoon of olive oil. Mix everything carefully and serve immediately.
Heat 3 tablespoons of olive oil in a frypan over a medium-high heat. Fry the onion for 5 minutes then add garlic and anchovies. Brown well for 1 minute mashing the anchovy pieces well with a wooden spoon.
Add the chilli, capers, olives and tomatoes and bring to the boil. Add salt and pepper. Reduce the heat to low and simmer for 10 minutes.
Meanwhile, cook the pasta according to packet instructions.
When the pasta is al dente and has been drained pour the sauce into the pasta saucepan.