Sauté the bacon for a few minutes in a little oil. Remove a few pieces of bacon for final garnish. Add the onion, courgette (reserve some slices for final garnish), and potatoes. Reduce the heat, cover the pan and allow to cook until the vegetables are soft. Stir in the stock and simmer for 10 minutes. Remove from the heat. Process the soup. Return to the saucepan. Stir in the cheese and cream and just heat gently. Add the reserved bacon pieces and courgette slices just before serving.