Ingredients

• 1 tbsp olive oil
• 1 clove garlic, crushed
• 1 onion, chopped
• 4 stalks celery, chopped
• 2 heads broccoli, cut into small florets
• 2 medium potatoes, chopped
• 160g bag watercress, spinach and rocket (or any mixed leaves)
• 4 pints vegetable stock
• a good grinding of black pepper