Heat the oven to 180ºC (350ºF).  Grease and line a tart dish.

Slice the onion.  Peel and dice the celeriac into 1.5 cm (1⁄2 in) chunks. Shred the green part of the chard leaves into strips.

Take the outer casing off the sausage and crumble it. Roughly chop the pecans. Dice the scamorza.

Saute the onion in 3 Tbsp of olive oil until it starts to become translucent. Add the sausage and saute until browned.

Add the diced celeriac, cover the pan and cook for 10 minutes, stirring frequently.  If the celeriac starts to stick to the pan, add 2 -3 Tbsp of water and stir.

Uncover the pan and add the chard.  Season with salt and pepper and leave to cook for another 5 minutes.

Let the tart mixture cool for 10 - 15 minutes.

Put the puff pastry in the tart dish, leaving the edges hanging over the sides.

Fill with the celeriac mixture.  Sprinkle the top with the Scamorza and pecans.

Fold the crust over the top of the filling.

Bake for 25 - 3à minutes until the pastry is a golden-brown colour.

The tart can be eaten hot or at room temperature.