Best: Curried Zucchini Soup

• 2 onions
• 1 celery stalk
• 1 garlic clove
• 1,400 ml vegetable stock
• 650 gr zucchini
• 16 ml vegetable oil
• 5 gr packed brown sugar
• 4 gr curry powder
• 2 gr salt approx
• 1 gr cinnamon