- 1 butternut squash (800g net), peeled and chopped into 2 cm pieces
- 1/2 teaspoon salt
- 1/4 teaspoon freshly ground black pepper
- 2 tablespoons olive oil
- 4 red onions (520g), end trimmed and chopped in half lengthways
- 3 large garlic cloves, skin on
- 1 litre (1 3/4 pints) of homemade chicken stock (use vegetable stock for a vegan option)
- 20 sage leaves
- 1/8 teaspoon salt
- 2 tablespoons extra virgin olive oil
- Preheat the oven to 180°C/355°F.
- Put the butternut squash pieces in a large metal roasting tray. Scatter over the salt and pepper, then drizzle over the olive oil. Toss until evenly coated. Arrange in a single layer, giving the pieces plenty of room to roast and caramelise.
- Arrange the red onions cut-side down in a separate roasting tray. Add the garlic cloves. Transfer both trays to the oven. Roast the onions and garlic until browned and soft – about 30 minutes. Roast the squash until browned and fork tender – about 45 minutes.
- Meanwhile, line a dinner plate with a couple of sheets of paper towel. Heat 2 tablespoon of olive oil in a small frying pan over a medium-high heat. When a few drops of water sizzle and evaporate upon contact with the pan, add the sage leaves. Fry until crisp but not brown – about 30 seconds. You will probably need to do this in 2-3 batches, as overcrowding will prevent the sage from crisping up. Transfer with a fork to the paper towel, and sprinkle over the salt. Set aside and leave to crisp up. Reserve the cooking oil to drizzle over the finished soup.
- When the roasted onions are cool enough to handle, peel off and discard the top layer or two of dark, dried skin, until you reach the shiny pink core. Slip the garlic cloves out of their skins (the easiest way to do this is to chop in half at the widest point, and then squeeze out using the back of a knife).
- Combine the roasted vegetables and the stock to a blender in batches, and blitz to the smooth puree.
- Transfer the pureed soup to a large saucepan and bring to the boil. Taste, and adjust the seasoning if necessary.
- Ladle the soup into bowls and serve hot, garnished with the fried sage leaves and a drizzle of the reserved cooking oil.