1 (about 1.2kg)turkey breast, skin on¼ cupcoarsely chopped flat-leaf parsley leaves2cloves of garlic, finely chopped15 gmfinely grated Romano Pecorino200 mlextra-virgin olive oil2Spanish onions, cut into wedges200 mlchicken stock80 ml (1/3 cup)rosé wine80 ml (1/3 cup)aged balsamic vinegar1head of radicchio, leaves separated and coarsely torn1cup (loosely packed) flat-leaf parsley leaves, coarsely torn
Preheat oven to 180C. Place turkey breast, skin-side down on a clean work surface, then, using a large knife, make an incision lengthways along the thickest part of the breast to butterfly. Open flap and season with sea salt and freshly ground black pepper.
Combine parsley, garlic, Pecorino and 30ml oil in a small bowl, season to taste, then spread evenly over turkey. Roll into a cylinder, tucking ends under, then tie at intervals with kitchen twine.
Scatter onion wedges over base of a small roasting pan, place rotolo on top, brush with 1 tbsp oil and season to taste. Add stock and wine to pan and roast for 30 minutes, then roast, basting regularly, for another 30 minutes or until golden and juices run clear when rotolo is pierced with a skewer.
Remove rotolo and onion from pan, cover with foil and rest in a warm place for 15 minutes. Meanwhile, place pan over medium-high heat, bring to the boil and cook for 5 minutes or until cooking liquid has reduced to a glaze consistency. Whisk in half of the vinegar and 80ml (1/3 cup) oil, season to taste and remove from heat.
Whisk remaining vinegar and oil together in a large bowl, season to taste, add radicchio and parsley and toss to coat. Serve rotolo, thickly sliced, drizzled with pan juices and radicchio salad passed separately.