Heat butter in a large saucepan. Add the onion and soften. Add the wild garlic and then the artichoke and continue to braise, deglazing with white wine as needed. Add the stock, cover with a lid and continue to cook until the artichokes are tender.

Add the cream and bring back to a simmer.

Remove from heat and add Parmesan cheese, spinach, lemon zest and chives. Season to taste and leave to cool completely.

To Make The Pithivier
Preheat the oven to 210 °C. Preheat a baking tray big enough to fit the circumference of the pithivier.

Lightly roll the pastry out on floured work surface and cut out a disc 28 cm in diameter.

Spread the chilled artichoke mixture over the disc, leaving the edge clear all the way around.

Roll the remaining pastry out and cut out a second disc 28 cm in diameter and place over the top of the first one. Press the edges down to seal. Brush with egg wash.

Use a sharp knife to score curved lines on top and at the edge of the pie.

Place the pithivier on the heated baking tray and bake for about 20 minutes. Reduce the oven temperature to 190 °C and continue to bake for further 20 minutes, until the top is golden brown and the pastry cooked through.

Allow to rest for 10 minutes before cutting and serving. Serve warm.