Peel, wash and cut the potato into dices, put in water.
Heat one tbsp oil in a pan or pressure cooker fry the vadis till golden then dish out them.
Add remaining oil in same pan, saute the ginger then fry the onion.
Add turmeric powder, red chili powder, coriander powder and salt, fry and add the tomato cook the massala with 1/2 cup water till the oil separates.
Now add potato and vadis stir 2 minutes, add 2 glass water, cover and cook on slow heat for 10 minutes.
Add garam masala, garnish with coriander leaves. Serve hot with rice or chapatis