Put the dried mushrooms in a bowl. Heat 150 ml of the milk in a small saucepan until it just comes to a boil. Pour it over the mushrooms and leave to soak for 11/2-2 hours. Keep pushing them down into the milk to make sure they soften. Once softened, pulse the mushrooms in a food processor until smooth and then pass them through a fine sieve.

Preheat the oven to 120 c/fan 100c c. Heat the remaining milk and cream together to boiling point. Take off the heat and whisk in the mushroom puree. Whisk the egg yolks in a separate bowl and gradually whisk in the mushroom milk until combined. Season with a little salt, pepper and nutmeg.

Pour the mixture into teacups or dishes and place in a roasting tin. Add enough water to come half the way up the sides of the dishes and bake for 1 hour or until set when shaken gently. Remove from the oven and set aside until completely cooled. Top with the demerara sugar and using a blow torch, caramelise the tops.

Meanwhile, make the garnish. Place the sherry vinegar and sugar in a small saucepan and bring to the boil stirring. Cook until the mixture is syrupy. Add the mushrooms and cook for 2-3 minutes until they are tender. Spoon on top of the brûlées to serve.