Peel the potatoes and cut into cubes. Soak them in a a bowl of cold water and agitate to remove some of the starch. When the water is turning white, drain and rinse the potatoes.
Boil some water in a saucepan, add a teaspoon of turmeric and salt, then reduce to a simmer. Boil the potatoes for 15-20 minutes, or until fork tender.
Meanwhile, finely chop the onion, garlic, chilli and ginger, and cut the tomatoes into quarters. Heat some oil in a pan, and add the dry spices and cook for 30 seconds before adding the onion with a pinch of salt. Cook the onion for 5 minutes.
Next add the chilli, garlic and ginger and cook for another minute. Add the dry spices and stir everything to combine, cooking until the spices release their aromas.
Add in the tomatoes, lemon juice and the water and cook down for another 10 minutes, stirring occasionally to prevent anything from burning. When the potatoes are cooked, drain them and add them into the spiced onion mixture and combine everything in the pan.
Add in the spinach, and cook until wilted.
