If you wish to use fried and mashed potatoes as in the original post. Fry peeled and cubed potatoes on medium flame until golden. (Also add a pinch of salt in the oil.) Then mash and use in the recipe. After frying the potatoes, fry the onions in the same oil. Then proceed with the recipe as directed. Fried potatoes definitely taste better than boiled ones but the difference is negligible.