Put the oil into a large sauté pan, for which you have a lid, and place on a medium high heat. Once hot, add the onion and fry for 8 minutes, stirring every once in a while, until soft and caramelised.
Add the Rose Harissa, tomatoes, olives, capers and ½ teaspoon of salt and continue to fry for 3–4 minutes, stirring frequently, until the tomatoes start to break down. Add 200ml of water and stir through.
Once boiling, reduce the heat to medium low, cover the pan and simmer for 10 minutes. Remove the lid of the sauce and continue to cook for 4–5 minutes, until the sauce is thick and rich. Stir in 10g of the parsley and set aside.
Meanwhile, fill a large pot with plenty of salted water and place on a high heat. Once boiling, add the pappardelle and cook according to the packet instructions, until al dente. Drain well.
Return the pasta to the pot along with the harissa sauce and 1/8 teaspoon of salt. Mix together well, then divide between four shallow bowls. Serve hot, with a spoonful of yoghurt and a final sprinkle of parsley.