2 lemons, zest and juice only
1 very small onion
1 small black truffle
200g/7oz Arborio rice
salt and freshly ground black pepper
1 litre/1戮 pints chicken or vegetable stock, heated to near boiling and kept warm on the hob
50g/2oz butter
parmesan cheese, to taste
125ml/4陆fl oz white wine or white vermouth