Bombay potatoes

Ingredients

• 1kg washed potatoes, chopped into 2.5cm cubes
• 15g ginger, peeled
• 3 garlic cloves
• 2 tomatoes, one quartered, the other cut into slim wedges
• ¾ tsp cumin seeds
• 1 tsp mustard seeds
• 2/3 tsp turmeric
• 2 tsp ground coriander
• 1 tsp ground cumin
• 1 tsp garam masala
• ½ tsp chilli powder
• Large handful of chopped coriander leaves
• Salt to taste