Red wine and radicchio risotto

Ingredients

• 3 tablespoons olive oil
• 1 small onion, finely chopped
• 2 cloves garlic, finely chopped
• 300g Arborlo rice
• 50cl Nebbiolo wine
• 600ml hot chicken stock
• 1 head radicchio (about 175g), halved, base trimmed and leaves sliced
• Salt and freshly ground black pepper
• 30g butter
• 45g Parmesan,grated, plus extra to serve