Remove the skin from the pancetta and finely slice it and set aside. Finely slice the garlic and brown onion.
Cut the Treviso in half then cut each half into 4 equal size wedges and set aside also.
Place a medium size frypan over medium heat.
Add a generous splash of evoo to the fry pan once it is hot and add the treviso wedges cut side facing down to the pan and pan fry the wedges on both sides until just beginning to colour. Once golden on each side remove the Treviso and set aside.
Add a little more evoo to the pan and add the slice pancetta and cook for 1-2 minutes until becoming crisp, next add the onion and cook for another 2 minutes before adding the garlic and sage leaves and cook for another 2 minutes.
Next add the green olives, caster sugar, balsamic and verjuce. Bring the mixture to the boil and return the treviso to the pot.
Place the frypan into a pre-heated oven steam 100 °C for 15 minutes.
Once cooked place all the ingredients and any sauce from the pan into a large serving bowl and finish with torn parsley leaves and shave manchego cheese and serve.