1. Wash, peel and chop the potatoes, carrots, and parsnips. Cook them in salted water for 10 to 15 minutes once the water has come to the boil then drain.
2. Preheat the oven to 180°C (Gas 4).
3. Slice the onions and fry them in a hot pan with a drizzle of olive oil, then add the potatoes, parsnips, and carrots.
4. Mix the eggs and 50 g of fresh cream, add a pinch of salt, nutmeg, and freshly ground pepper.
5. Remove from the heat, add the fresh cream mixture, and stir.
6. Roll out the puff pastry in a pie dish and spread the rest of the fresh cream over the bottom.
7. Pour in the potato mixture and sprinkle with grated Cheddar cheese. Bake for 15 minutes.
8. Serve with salad

Tip: To be eaten hot. For a touch of character, replace the Cheddar with a blue cheese or extra-mature Cheddar.