1. Mix the flour and salt with the sesame/poppy seeds. Add the cold butter in small pieces and rub it in with your fingertips. When the mixture resembles fine breadcrumbs, add the beaten egg and knead together, finishing with the well-chilled water. Bring together into a ball, cover with cling film and leave in the refrigerator.
2. Thoroughly grease your pie dish with butter. Roll out, turning the pastry occasionally to achieve an even result. Place the pastry into the pie dish, pushing it down. Cut off the extra pastry level with the top of the dish. Refrigerate for around 30 minutes.

THE FILLING

1. Peel the butternut squash. Cut into half and remove the seeds in the lower part of the squash. Next cut it into cubes. Heat up a dutch oven with a steaming basket, add the butternut squash pieces in to the basket. Put on the lid and leave to cook for 20-30 minutes. Remove the steaming basket and set aside.
2. In a small bowl, beat the eggs, mustard and cream together. Add a pinch of salt and a grind of pepper. Set aside.
3. Take the pastry and prick with a fork, cover with a piece of parchment paper and pour dried lentils, beans or chickpeas on top, pre-bake the pastry for 30 minutes in the oven pre-heated to 160 C. Once the pastry is pre-cooked, remove the beans and parchment paper and brush the bottom of the tart with beaten egg and return it to the oven for 3 minutes. Remove the pie crust from the oven and adjust the oven heat to 180C.

TO COMPLETE THE TART

1. Place the cubes of cooked butternut over the surface of the tart. Pour over the egg and cream mixture, spreading it evenly. Cut shavings of Roquefort and cover the surface.
2. Sprinkle with ground nutmeg to taste. Scatter with flat chopped parsley.