Heat the oil in a pan and sweat the onions and celery under a lid until soft but not coloured (about 10 minutes, stirring occassionaly).

Add the courgettes, garlic and potato and fry until the courgettes turn golden, turning with a wooden spoon.

Add the stock, salt and pepper and replace the lid.

Bring to the boil and then lower the heat to a simmer for 15 – 20 minutes (until potatoes are cooked).

Blend the soup until smooth and check the seasoning.

Serve with crusty bread.