Nutrition: Per serving
Heat the oven to 200C/180C/gas 6. Pit the squash on a baking sheet and toss with 1 tbsp of the oil and a pinch of salt. Roast for 25-30 mins or until tender.
Heat the remaining oil in a casserole dish or saucepan with a lid. Add the onion and celery with a pinch of salt and fry over a low-medium heat for 10 mins, or until softened and translucent. Add the garlic, chilli and butterbeans and cook for 1 min more. Add the roasted squash with the stock, thyme and vinegar. Cover with the lid and cook over a medium heat for 10 mins.
Remove and discard the thyme. Blitz half the soup with a stick blender, leaving some whole bits of squash. Ladle the soup into bowls and top with a swirl of fresh pesto and a dollop of yogurt. Serve with hunks of crusty bread.
