Heat oil in a large saucepan over medium-high heat. Cook onion, garlic, carrots and salt, stirring occasionally, for 5 minutes, or until vegetables are tender.
Pour stock and water into the pan, and bring to a boil. Add potatoes and tomato paste. Return to a boil. Stir in chilling powder, cumin and herbs.
Reduce heat to low and cook on a gentle simmer, covered for 20 minutes until potatoes are cooked
Season to taste and serve
