1. Preheat the oven to 180°C.
2. Grease a 22cm loose-bottomed flan tin, (or if you prefer, you can roll the pastry into a rectangular baking sheet) and line with the pastry.
3. Overlap the sheets and press them into the base and up the sides of the tin.
4. Trim the edges neatly, allowing for some shrinkage, prick the bottom with a fork and chill for 30 minutes.
5. Remove from the fridge, line with greaseproof paper and pour in enough dry beans to cover the base of the tin.
6. Bake the pastry blind for 10 minutes, then remove the paper and beans and set aside to cool completely.
7. Heat the butter and gently cook the onions, and butternut until soft and golden.
8. Let them cool completely, and then spoon half the mixture onto the pastry base. Top with the cheddar cheese and the parsley.
9. Beat together the eggs, cream, nutmeg, flour, salt, pepper and chives, thyme and spring onions.
10. Gently pour into the pastry case, arrange the remaining butternut mixture onto the tart and dot with feta cheese.
11. Bake for 30 - 35 minutes at 180°C or until set and golden.