Boil potatoes in large pot until tender, about 15 minutes. Drain water and set aside.
Heat oil in a large saucepan on medium-high heat, add cumin seeds until sizzling. Add onions and cook until soft, about 3 minutes.
Add garlic and ginger and cook for another minute, stirring constantly
Add coriander, cumin, turmeric, paprika.
Stir in spinach and cook stirring until wilted, about 2 minutes.
Season with salt. Add potatoes and stir occasionally for flavors to blend, about 3 minutes.