1Peel and dice the potatoes into small cubes.
Finely chop the onion, garlic, and ginger.
Heat the vegetable oil in a large pan over medium heat.
Add the chopped onion to the pan and sauté until it becomes translucent.
Add the garlic and ginger to the pan and sauté for another 2 minutes.
Stir in the curry powder, cumin, turmeric, and chili powder, and cook for 1 minute to release the flavors.
Add the diced potatoes to the pan and stir to coat them with the spices.
Pour in the diced tomatoes and coconut milk, and stir well.
Bring the mixture to a boil, then reduce the heat to low and let it simmer for about 20 minutes, or until the potatoes are tender.
Add the spinach to the pan and cook for another 5 minutes, or until the spinach is wilted.
Season with salt to taste.
Serve hot with rice or naan bread.