Score the porchetta down through all the rinds and sprinkle with flaky salt.
Mix all the ingredients for the compote in a pan.
For the raw-pickled rhubarb. Boil water with sugar and cool. Place the thin slices of rhubarb in a jar and add the vanilla pod. Pour the cooled sugar syrup over.
Grill
Set and preheat the grill to 185° C. When the grill is hot, place the porchetta on the grill rack. Grill it until it has a core temperature of 70° degrees, about 90 minutes.
Place the pan with the rhubarb compote on the grill for about 30 minutes. Stir it regularly.
Split the burger bun and grill them on all 4 sides.
Arrange
Spread the burger bun top and bottom with rhubarb compote.
Place a handful of arugula and some parmesan cheese on the bottom of the bun.
Cut the porchetta and place 2 slices on the burger bun bottom.
1 tbsp green pesto and a few of the pickled rhubarbs.
Finish with crushed pork rinds and the top of the burger bun.