Nutrition per portion
- 4 fennel bulbs
- 3 medium leeks
- 50g (2oz) butter
- 2 tbsp flat-leaf parsley, chopped
- 1tbsp thyme leaves, chopped
- 225ml (8fl oz) chicken or vegetable stock
- 225ml (8fl oz) double cream
- you will need
- a shallow baking dish approx 25.5cm x 25.5cm (10x10in)
Remove any tough outer layers from the fennel. Split lengthways, remove the core and cut crosswise into 6mm (¼in) slices. Trim the root and dark green tops from the leeks, halve them lengthways and cut crosswise into 6mm (¼in) slices. Wash and drain well.
Melt half the butter in a large sauté pan, add half the fennel and cook for 5 minutes until just beginning to soften. Transfer to a large mixing bowl and cook the remaining fennel in the same way. Melt the remaining butter and cook the leeks in the same way until just soft. Transfer the leeks to the same bowl as the fennel. Add the herbs and plenty of salt and pepper. Pour in the stock and cream, mix well, then transfer to a large baking dish.
Heat oven to 190C, 170C fan, 375F, gas 5. Bake the gratin for 45 minutes to 1 hour. The top should be nicely browned, the cream bubbling and the vegetables tender.