Peel and roughly chop up the onion and the celery Take a large sauce pan and add the chopped onions, celery and the tbsp of rapeseed oil and place over a gentle heat.
Sweat the onions and celery until they are translucent, then add the finely chopped garlic and allow to soften, constantly stirring so that the onions, celery and garlic don't brown.
Dissolve the vegetable stock cube in the water and add to the onions, celery and garlic. Add the potato cubes to the stock and gently allow to simmer.
When the potato is cooked through completely, add the broccoli adding the florets to the watery stock. Be sure to use the broccoli stalk as well, cutting this into smaller chunks. Cook for 5-6 minutes until the broccoli stalk chunks are tender but still have a slight bite.
Turn off the heat and add the watercress and rocket leaves, spring onions and finely chopped parsley leaves. Leave for 30 seconds with the lid on, giving the leaves just enough time to wilt.
Now take a hand blender and blend thoroughly, adding salt and pepper to taste.
Toast the pine nuts in a dry frying pan, keep constantly stirring over a low heat, and allow the pine nuts to gently brown, without burning. When the pine nuts start giving off their nutty aroma, remove from heat and set aside.
Bring the soup back up to heat, and portion out into appropriate bowls, and add the toasted pine nuts as a tasty topping.