Confit Tuna with White Beans, Celery and Radicchio

What you will need

900 kg skinless yellowfin tuna, cut into 5cm cubes

2 fresh bay leaves

2 tarragon sprigs

1 tbsp fennel seeds

1 tbsp white peppercorns

1 star anise

Thinly peeled rind of 1 orange

1 tbsp coarse sea salt

400 gm (2 cups) dried cannellini beans, soaked overnight in cold water

1.5 litres mild-flavoured extra-virgin olive oil

1 Spanish onion, thinly shaved

3 celery stalks, finely diced

½ radicchio, coarsely torn

1 cup (firmly packed) young celery leaves

1 cup (firmly packed) flat-leaf parsley leaves

To taste: aged red wine vinegar