Ingredients:
Potatoes - 900 gms, boiled, cubed
Dry Red Chillies - 5, cut into half
Vegetable Oil - 5 tbsp
Mustard Seeds - 1 tsp
Onions - 1/2 cup, chopped
Garlic - 4 tsp, chopped
Ginger - 4 tsp, chopped
Red Chilli Powder - 2 tsp
Turmeric Powder - 1 tsp
Coriander Powder - 2 tsp
Salt to taste
Tomatoes - 300 gms, skinned, chopped
Green Chillies - 3, chopped
Lemon Juice - 1 tbsp
Butter - 4 tsp

Method:
1. Heat the oil in a pan.
2. Add the dry red chillies and mustard seeds.
3. Saute over medium heat until they begin to crackle.
4. Add the onions, garlic ginger and saute over high heat for 5-6 minutes.
5. Add the red chilli powder, turmeric powder, coriander powder and stir well.
6. Add the tomatoes and simmer on low heat until the oil separates from the gravy.
7. Add the potatoes, green chillies, lemon juice and butter.
8. Cook for 5 minutes.
9. Remove from heat and serve.