Spicy Tomato and Lentil Soup

Ingredients

• 1 large brown onion, chopped finely
• 1 large carrot, chopped into 2cm sized pieces
• 1 stick celery, sliced thinly
• 1 tablespoon olive oil
• 1 tablespoon mild curry paste
• 2 cups (or 1 x 500ml tetra pack) of chicken or vegetable stock
• 1 cup water
• 100g red lentils, rinsed and drained
• 1 x 800g can of tomatoes, diced or chopped
• 1 tablespoon tomato paste
• 1 teaspoon dried herbs (parsley, basil or mixed herbs)
• black pepper, to taste
• 1/4 cup low-fat plain yoghurt