Heat the oil in a large saucepan. When it's bot, add the mustard seeds.
When they begin to pop, add the cumin seeds and chillies. Let them sizzle for 10 seconds.
Add the chopped onion to the pan and cook for 5 mins.
Cook the potatos until soft then add the chopped potatoes and tomatos, tomato paste and water and fry for 5 mins. Microwave the spinach first then add the spinach a bit at a time.
Tightly cover the pan and cook for 10 mins.
Stir in the spices (salt, turmeric, cumin, coriander), reduce the heat and cook gently for 10 mins. Serve with rice and naan bread.
It isn't spicy neither, I would say it is suitable for a one year old.