Updated: Sep 6, 2022
When I was growing up, we had Bengali neighbors who occasionally treated us to food from their kitchen. Every afternoon as I walked home from school and passed their living room window, through the common area, I would have a sensory overload from the aromas coming from their kitchen. It's one of the fondest memories of food that I have from my childhood and one that I can't forget because of the distinct fragrance of mustard oil.
Mustard oil is used as primary cooking fat in the states of West Bengal, Assam, Orissa, Kashmir, Punjab, and Uttar Pradesh. There's little or no cooking done in mustard oil in Kerala; coconut oil is used instead. Other Indian states use a variety of vegetable and nut oils, including ghee (clarified butter).
Known for its sharp, pungent aroma, you can smell mustard oil before you see it because it contains a sulfur compound called allyl isothiocyanate, which is also found in wasabi and horseradish. Because of this, a whiff of mustard oil can clear your sinuses. It has a strong smell with a slightly bitter tinge, so it's always heated until it reaches the smoking point first to tone down its pungency.
Unlike saturated and refined fats, mustard oil is made using the kachi ghani or cold-press process, where mustard seeds are crushed at a very low temperature without using any chemicals or preservatives. This helps retain the natural antioxidants in the oil.
Mustard oil can withstand high temperatures and absorbs flavors, which makes it ideal for Indian cooking, including deep frying. It can also finish a dish, as with the famous Bengali dish called posto bata, which is a ground poppy seed paste, spiked with chilies and raw mustard oil.
Eye-wateringly sharp, it can be considered an acquired taste, but everything – including fish, meat, vegetables, and lentils – can be cooked in it. Even the world-famous tandoori and butter chicken dishes use it. Most Indian pickles are also made with mustard oil because of their antibacterial properties.
One of my favorite recipes is alur dom, which is a Bengali version of curried potatoes. It takes me back to my neighbors' kitchen where I ate many a bowl of alur dom with deep-fried luchi (bread). Baby potatoes are deep-fried in spiced mustard oil and then cooked in a light tomato- and yogurt-based sauce. The potatoes soak up the flavor of the oil and spices, and the tangy sauce is light and delicious.
Mustard oil is not just an ingredient, it's a part of my happy childhood memories, where we ate many lunches and dinners with this oil. It truly has a special place in my heart and kitchen.
500 g baby potatoes
¾ cup mustard oil
2 dried red chilies
2 bay leaves
1 tsp nigella seeds
1 cinnamon stick
2 star anise
1 ½ tsp turmeric
1 tsp Kashmiri red chili powder
1 tsp ginger paste
2 green chilies
1 cup yogurt
4 large ripe tomatoes
Salt to taste
1) Boil the baby potatoes with salt until tender. Drain the water and peel them immediately. Then, prick each potato with a toothpick. This will allow the potatoes to soak up the spices and oil.
2) Blanch the tomatoes in hot water until their skins start to peel slightly. Cool to room temperature and add to a grinder with green chilies, ginger paste, and yogurt. Blend until smooth. It's important to ensure that the yogurt is at room temperature and that the tomatoes are not hot, or else the sauce will split.
3) Heat mustard oil in a pan until it reaches the smoking point. Reduce the heat and add ½ tsp turmeric powder and 1 tsp red chill powder. Fry the potatoes until they are golden and crispy. Put them aside on a paper towel to absorb excess oil.
4) If there's enough oil in the pan, you can reuse it, or you can add 1 tbsp of mustard oil in the pan and heat it again. Reduce the heat and add the dried red chilies, bay leaves, cinnamon, nigella seeds, and star anise.
5) Gently pour the tomato and yogurt mixture, the rest of the chili and turmeric powder, and salt to taste. Bring it to a rolling boil before adding the potatoes to the sauce.
Cook on a low flame for another ten minutes, then turn down the heat ready to serve.