Coriander potatoes with chickpeas and tomatoes

Ingredients

• 2 tablespoons olive oil
• 1 large brown onion (200g), sliced thinly
• 2 cloves garlic, crushed
• 2 teaspoons ground cumin
• 2 teaspoons ground coriander
• 4 medium potatoes (800g), sliced thickly
• 400 grams can crushed tomatoes, undrained
• 1 tablespoon tomato paste
• 1 teaspoon sugar
• 1 1/4 cup (310ml) water
• 300 grams can chickpeas, rinsed, drained
• 1/4 cup fresh coriander leaves, finely chopped