In a deep bottomed pan, heat 4 tbsp. oil (vegetable/light olive oil)
As the oil heats up, sauté 1 tsp paanch foran (see notes below on Paanch Foran),
1 sprig of curry leaves, 1 pinch Hing
Add 1 tsp ginger, jeera and coriander paste and sauté well on medium to low heat
Add 4 medium sized chopped tomatoes, 1 tbsp. turmeric, 1tbsp. red chili powder (less if you don't want the gravy to be very spicy) and 2 tbsp. salt. Cook on medium heat covered till the tomatoes are well cooked and the oil separates
Add 6 medium sized potatoes (skin on) cubed into bite sized pieces
If you are adding the dal (cooked lentil), add 2 tbsp. cooked dal or 1tbsp. uncooked masoor dal at this point.
Sauté and cover. Cook on low to medium heat till the potatoes are cooked through.
Add water per your taste (start with a cup of water and add more as you like) and simmer for 10 minutes making sure flavors are absorbed well
Cook on low heat for another 15/20 minutes. Finally, add 2 tbsp. chopped cilantro and enjoy aloo tamatar ki sabji.