1. Remove the outer leaves of chicory heads and set aside. Boil the remaining chicory in salted water for 40 minutes until soft. Leave to cool in a colander, then press lightly to get rid of any excess water.
2. Take a heavy bottomed 25cm diameter frying pan, butter the bottom of the pan and sprinkle the sugar over the top.
3. Chop the chicory into 5cm pieces and stand in the bottom of the pan.
4. Cover the chicory with the 25cm round of pastry, pressing the sides well down into the pan. Prick pastry and leave in fridge for 20 minutes.
5. Place pan on medium heat hob and cook until the butter bubbles and the sugar starts to caramelise.
6. Then place pan in a pre-heated oven at 200°C/400°F/ Gas Mark 6 for 30 minutes until the pastry is golden.
7. Turn the tarte out onto a dish so the chicory is facing upwards.
8. Garnish with crumbled the Roquefort and the remaining chicory leaves and serve.