Cook the spaghetti following pack instructions, then drain, reserving 150ml of the cooking water. Meanwhile, heat the oil in a large non-stick pan over a medium heat. Add the aubergine and garlic, stir well, then cover and cook for 8-10 mins, stirring a few times.

Mix in the tomato purée and vinegar, and cook for 2-3 mins more. Pour in the stock, then cover and cook for a further 10-15 mins until the aubergine is tender when pierced with a knife.

Add the cherry tomatoes and cook for a few minutes more until softened but still holding their shape. Stir in the basil, capers and walnuts, then toss through the spaghetti, adding a little of the reserved pasta water if needed to loosen. Serve half straightaway. Keep the remainder for another day. Will keep covered and chilled for up to four days. Reheat in a pan over a low heat with a splash of water until piping hot.