500g/1lb 2oz celeriac, peeled, cut into chunks
500g/1lb 2oz floury potatoes, peeled, cut into chunks
1 garlic clove, finely diced
1 sprig rosemary, leaves finely chopped
1 banana shallot, finely sliced
2-3 sprigs fresh thyme, leaves only
200g/7oz tinned tomatoes
200ml/7fl oz chicken stock
400g/14oz tinned flageolet beans, drained and rinsed
salt and freshly ground black pepper
approx 15g table salt (you will need 15g/陆oz salt per kilo of duck legs)
50g/2oz butter
75g/3oz butter
110ml/4fl oz double cream
300g/11oz duck fat
4 duck legs