Butternut squash, onion and chestnut tarte fine

Celebrate autumn with this vegetable tart by Bryn Williams, boasting butternut squash, earthy sage and chestnuts galore.

Ingredients

For the dressing

• 500ml/18fl oz vegetable oil
• ½ tbsp white peppercorns, lightly crushed
• ½ shallot, peeled and chopped
• 100ml/3½fl oz white wine vinegar
• 25g/1oz Dijon mustard
• 25g/1oz English mustard
• 10g/⅓oz salt

For the butternut, onion and chestnut tarte fine

• 2 tbsp olive oil
• 6 onions, sliced
• 250g/9oz cooked chestnuts, plus extra for serving
• pinch chopped fresh sage
• plain flour, for dusting
• 500g block ready-made puff pastry
• 1 medium free-range egg, beaten
• 1 butternut squash, peeled, halved and cut into 5mm/¼in slices
• 2 tbsp honey
• pinch sea salt

To serve

• oil, for frying
• handful fresh sage leaves
• 1 Treviso radicchio (red long), leaves separated
• handful dandelion leaves

Method

1. To make the dressing, mix all the ingredients together in a sealable container and place in the fridge. Leave for 24 hours.

2. The next day, use a hand-held stick blender to blend the mixture until smooth. Pass the dressing through a fine sieve and set aside.

3. To make the tarte fine, heat the olive oil in a frying pan over a medium heat, then add the onions and cook for 5–8 minutes, until soft. Add 100g/3½oz of the cooked chestnuts to the pan along with a pinch of chopped sage and cook until the chestnuts have broken down. Leave to cool.

4. Preheat the oven to 220C/200C Fan/Gas 7. Line a baking tray with baking paper.

5. Dust a work surface with flour, then roll out the puff pastry into a rectangle measuring 13x30cm/5x12in. Prick all over with a fork.

6. Brush the sides of the pastry with the beaten egg, then fold in by about 1.5cm/⅝in.

7. Spread a thin layer of the onion and chestnut mixture onto the puff pastry, then place the butternut squash slices on top, making sure it covers the onion but not the folded sides. Drizzle with honey and olive oil then sprinkle with sea salt and bake for 20 minutes or until the pastry and butternut squash are cooked.

8. To serve, pre-heat a small frying pan and add 4 tbsp olive oil. Once hot add the whole sage leaves and fry for 1–2 minutes, until crisp, being careful not to let them burn. Place on a plate with kitchen roll to absorb the excess oil.

9. Toss the radicchio and dandelion leaves together with the dressing. Cut the tart into three pieces, place the dressed leaves over one corner and finish by slicing the remaining chestnuts over the top and adding the fried sage leaves.

Butternut squash, onion and chestnut tarte fine