Add the olive oil to a saucepan over a medium heat, then add the red onion, garlic, chilli flakes, olives, sun-dried tomatoes and capers and cook for 4-5 minutes.
Then, add the tinned tomatoes and vegetable stock and bring to the boil. Once boiling, add the spaghetti to the pan and cook for 10-12 minutes until the spaghetti is cooked and the sauce has thickened. Season to taste and sprinkle with chives.
