Peel and cut your potatoes into 1-inch cubes and place them into a pot of boiling water.
Boil for 8-10 minutes or until fork tender but not mushy.
In a separate pot, heat the oil on medium heat and add the finely chopped onion, garlic and ginger paste, and spicy pepper, if you're using.
Sauté until everything is fragrant and softened, about 5-10 minutes.
Add in the drained potatoes & frozen peas and mix.
Add the spices and the tomato purée and mix.
Finally, add in the water and mix lightly.
If you like it to be more stew-like, add more water.
Cover and let it simmer on low for 5 minutes until everything is softened and the flavors are all absorbed.
Serve with white rice or naan.