Hot curry-ginger lentil and vegetable soup

Ingredients

• 1 big onion
• 1 branch celeri
• 1 big or 2 medium carrots
• 2 cloves garlic
• 1 zucchini
• 6-7 button mushrooms
• 1 piece fresh ginger the size of a golfball
• 1 big potato
• 1/3-1/2 cup lentils
• 4 cups chicken or vegetable stock
• salt, pepper to taste
• 1 TBSP brown sugar
• 1 TBSP oil