Jerusalem Artichoke & Rocket Soup

Ingredients
1kg Jerusalem Artichoke washed, peeled and keep in lemon water. Half a lemon is enough. 1 Large potato, washed, peeled and sliced. 2 White onions thinly sliced. 1 Garlic clove, crushed and chopped. 1 litre White Chicken stock or Clear Veg stock 50ml Fresh Cream 100ml of Olive Oil * Optional Finely shredded Rocket leaves right at the end. Garnish with a swirl of good Extra Virgin Olive oil and some slivers of Fresh Parmesan. Serve with some nice crusty, warm bread and enjoy!
Instructions
Heat the oil, fry off the onions, potatoes, artichokes lightly, without giving them colour. Add the garlic and fry lightly. Then add the stock, bring to the boil. Then bring down the heat and simmer till all the vegetables are tender. Liquidise the soup and pass through a strainer if a finer soup is desired, otherwise just return to the pot, bring to a light simmer, add the cream, season and serve.