Place the whole, unpeeled potatoes in a pot and cover with water. Cover the pot and bring to a boil, then reduce the heat to a simmer. Cook until easily pierced with a knife - 15 to 20 minutes. Remove the potatoes and set aside to cool. Once cool, peel the skin and cut them into small cubes.
Meanwhile, prepare the spinach sauce. If using whole mature spinach, cut out the thick stems and roughly chop the leaves. If using baby spinach, no prep is necessary.
Bring a medium pot of water to the boil. Once boiling, turn off the heat and add the spinach to blanch it. Baby spinach only needs about 30 seconds. Mature spinach may need a couple of minutes. It’s ready when it’s tender and bright green.
Optional: to maintain the bright green colour, transfer the blanched spinach to a bowl of ice water. Most of the time I’m too lazy and just run it under cold water in a colander.
Allow the excess water to drain off the spinach and transfer it to a food processor along with the ginger, the one clove of roughly chopped garlic and the chili pepper. Blend to a sauce. If the processor is having a hard time getting going, add a couple tablespoons of water.
In a saucepan, heat the oil over medium heat. Once hot add the cinnamon, cloves, cardamom and cumin. Fry, stirring frequently, until the cumin darkens slightly in colour and the spices are very fragrant - 1 to 2 minutes.
Add the onion and fry until soft, then add the two minced cloves of garlic and fry until soft. Now is a good time to remove the cinnamon, cloves and cardamom pods.
Add the tomato and fry until soft - about 3 - 4 minutes. Squish the tomato with the back of your spoon into a paste.
Add the garam masala and turmeric and cook for 30 seconds to bring out the flavours. Add the pureed spinach and cook for 1 - 2 minutes to cook out the raw ginger and garlic.
Add the cubed potatoes and as much water as necessary to reach the consistency that you like. I like a bit of sauce so I add about ¼ cup (60 ml). Simmer for a couple of minutes until the potatoes are heated through. Add salt and you can add additional garam masala if you think it needs a bit more flavour.