- 2 leeks, cut into 1cm/½in slices
- 2 fennel bulbs, cut into 1cm/½in cubes
- 600g/1lb 5oz squash, peeled and cut into 15mm/⅝in cubes
- 2 tbsp olive oil
- 1 tsp sea salt flakes
- ½–1 tsp chilli flakes, to taste
- 20g/¾oz tarragon, leaves only
- 400ml/14fl oz double cream or crème fraîche
- 100g/3½oz hazelnuts, roughly chopped
- 75g/2¾oz mature cheddar, grated
Preheat the oven to 220C/200C Fan/Gas 7. Tip the leeks, fennel and squash into a roasting tin large enough to hold everything in roughly one layer, then stir through the olive oil, salt, chilli and half the tarragon. Roast for 45 minutes, or until the squash is just cooked through.
Meanwhile, finely chop the remaining tarragon leaves.
Pour the cream or crème fraîche over the vegetables, then scatter with the chopped tarragon, hazelnuts and cheddar. Turn the oven down to 200C/180C Fan/Gas 6 and return the gratin to the oven for a further 15 minutes.
Leave the gratin to cool for 10 minutes before serving, with crisp rounds of toasted bread.
Fennel, leek and squash gratin with tarragon and hazelnuts