Peel and chop the potatoes. Put them in a pan, cover with water and add the garlic cloves (whole), bay leaf and peppercorns and some salt. Boil until the potatoes are soft, then drain them, saving the cooking water for stock. Puree the potatoes by pushing them through a sieve or mashing them.
Chop the onion and grate some of the rind from the lemon (alternatively, you could slice it off thinly and cut it into very fine strips). Fry the onion until it is starting to brown, then add the rind and give it a quick stir before pouring in some of the stock. Squeeze the juice from the lemon into the pan (use your cupped hand to catch the seeds and let the juice escape between your fingers). Pour the mixture from the frying pan into a soup pot, add the potato puree and the rest of the stock and bring to the boil. Thin the soup with water and add salt as necessary. Simmer for ten minutes then switch off the heat and add the chopped herbs.
more potato recipes