Ingredients:
* 2 heads fennel, each about 300 g (10 oz), trimmed and quartered lengthways
* 125 g (4 oz) closed cup mushrooms, thickly sliced
* 1 tablespoon lemon juice
* 2 tablespoons water
* 1 teaspoon sugar
* 1 tablespoon finely chopped fresh parsley
* 25 g (1 oz) butter
* salt and freshly ground black pepper
* fennel leaves, to garnish