Lamb, chickpea & spinach curry with masala mash

INGREDIENTS

• 1 tbsp oil
• 500g lean lamb stewing cubes
• 1 red onion , sliced into half moons
• 1 cm piece ginger , peeled and finely chopped
• 2 garlic cloves , crushed
• 1 tbsp ground cumin
• 1 tbsp ground coriander
• 400g can tomatoes
• 200g can chickpeas , washed and drained
• 1 tsp garam masala
• 100g spinach , roughly chopped
• 700g potatoes , peeled and quartered
• 1 tbsp korma curry paste (we used Patak's)
• 100ml thick yogurt