Spicy and Sour Tomato Lentil Soup (Rasam)

This week marks the publication of my friend Chitra‘s cookbook, Vibrant India. If you’ve been reading this blog a while—or if you just like home cooking as much as I do—you may have found that cheap, healthful, and seasonal are some essential beacons to guide everyday recipes. And Chitra’s home cooking—and, hence, her cookbook—have these traits in spades.

In fact, if there was ever an award for packing the most flavor AND nutrition into the least amount of cost for the ingredients, South Indian cooking, which is Chitra’s foundational cuisine, might win top honors. She writes lovingly in the introduction to Vibrant India how her grandmother often cooked for up to twenty people, three meals a day: “Her cooking was streamlined to produce large quantities of quickly prepared, delicious food that fit into a tight budget.” Given that kind of challenge, who can complain about not eating out in New York by cooking for yourself more often?

And what can we gain from that kind of legacy in our everyday kitchens? A lot, I’ve found. Thanks to Chitra, I’ve gained a deeper appreciation for lentils, which I never ate too much growing up but have since fashioned into “risottos” and many daals. I’ve learned to spike unassuming side vegetable dishes with plenty of fresh herbs and spices like in this pea and lima bean salad, which I brought to Chitra’s birthday picnic once. And I’ve also found that you can make a traditional tomato-based saaru (or saru or rasam) befit any occasion. Like with Chitra’s Saru Gazpacho, a winning dish from a summery cook-off I once hosted where she served the lentil and tomato soup chilled, for a change.

That’s pretty much the recipe that I’ve made here from her book, only it’s hot. And perfect for these chilly first days of spring.

The recipe is called Spicy and Sour Tomato Lentil Soup (Tomato Bele Saaru or Rasam) in the book, and I might add that it’s a little bit sweet, too. This (and the sourness) comes from a pinch of tamarind paste, as well as the tomatoes, which Chitra notes are phenomenal if found fresh at the peak of their sweetness in the summer; the rest of the year, she uses peeled and diced San Marzanos. The spiciness comes from rasam powder, which is a spice blend typically homemade in South Indian kitchens; you can also find the blend store-bought. It varies a little bit, but includes ground dried red chilies, cumin, coriander, black mustard seeds, fenugreek seeds, black peppercorns, asafetida, and turmeric. Some people add curry leaves and Chitra says that one of her aunties adds a pinch of cinnamon powder to the mix, which you can if you like, too.

For serving suggestions, you can add a dollop of plain yogurt and fill it out with some rice and a vegetable side for a full meal. Chitra would also add some of her Brooklyn Delhi achaar, the rhubarb ginger kind if you like a bit more zing. Personally, this soup was vibrant enough for me alone. It’s like tomato soup and lentil soup, but with so much more flavor. Best part—like with most soups—it just gets better as the days go by.

Hear more from Chitra on this week’s episode of Eat Your Words, and get your hands on Vibrant India for many more dishes like this.

Spicy and Sour Tomato Lentil Soup (from Vibrant India: Fresh Vegetarian Recipes from Bangalore to Brooklyn, 2017 Ten Speed Press)
(makes 4 servings)

1 cup red lentils
1/4 teaspoon turmeric powder
3/4 teaspoon salt
1 14.5 oz can diced tomatoes (or 4 medium-sized fresh tomatoes, about 1 lb)
2 teaspoons saaru powder
1/2 teaspoon salt
3 cups water, plus more as needed
1 teaspoon granulated jaggery or brown sugar
1 teaspoon tamarind paste
1 tablespoon ghee, unsalted butter, or canola oil
1/2 teaspoon black mustard seeds
pinch of asafetida (hing) powder
1/2 teaspoon cumin seeds
pinch of ground cinnamon
2 or 3 fresh curry leaves
chopped cilantro leaves, for garnish
plain yogurt, for garnish (optional)
cooked rice, for serving (optional)

Wash the lentils thoroughly. Add lentils to a saucepan with 4 cups of water. Bring to a boil. Monitor the foaming, and skim off the foam. Mix in the turmeric powder. Turn heat down to medium-low, partially cover, and simmer until cooked through, about 25 minutes. Mix in the 1 teaspoon salt.

In another pot, combine the tomatoes, saaru powder, 1/2 teaspoon salt, and 1 cup of water. Bring to a boil and cook over medium-high heat for 5 minutes. Make sure the saaru powder has dissolved; add the jaggery/sugar and tamarind paste. When the soup is red and the tomatoes are falling apart, add the cooked lentils to the pot. Add the remaining 2 cups of water to the pot, bring to a boil, then continue to simmer for 10 minutes.

During this time, adjust the water quantity to your preference. Taste for sourness and add more tamarind paste if needed. If adding more tamarind, boil the saaru a couple more minutes for the flavors to meld.

Put the ghee in a tempering pot or small pan over medium heat. When melted, add one black mustard seed. When the seed sizzles and pops, add the rest of the mustard seeds and the asafetida. Keep a lid handy to cover the pan while the mustard seeds are popping. When the popping starts to subside (a few seconds), stir in the cumin seeds and cinnamon. When the seeds turn a darker shade of brown (a few seconds), turn the heat to medium-low. Rub the curry leaves between your fingers a little to release their natural oils, and drop them into the ghee. Cover immediately, as the moisture from the curry leaves will cause the ghee to splatter. Then stir to evenly coat everything with the ghee, a few seconds. Turn off the heat.

Immediately pour the spiced ghee over the saaru. Taste for salt and adjust as needed. Garnish with chopped cilantro leaves.

Cost Calculator
(for 4 servings)

1 cup red lentils: $0.50
14.5 oz can diced tomatoes: $2.50
1 teaspoon tamarind paste (from a block for $4): $0.25
1 teaspoon brown sugar: $0.10
1 tablespoon ghee: $0.25
2 teaspoons saaru powder (gifted to me by a friend): $0.25
turmeric, cinnamon, mustard seeds, cumin: $0.25
curry leaves: $0.25
asafetida: $0.25
¼ bunch cilantro: $0.50

Total: $5.15

Health Factor

Three maple leaves: It’s no old wives’ tale that eating lentils will make you smart. Lentils, and most legumes (or pulses, as the Brits would say) are widely hailed as an essential part of a heart-healthy diet. They are packed with protein and fiber, as well as calcium, potassium, and iron. Makes you wonder why all the fuss over fake meat innovations today, when you can just eat more of them. This recipe could use a green side, as Chitra advises in her serving suggestions, and using fresh tomatoes when in season in the summer could save you from the added sodium that canned tomatoes often come with.

Green Factor

Eight maple leaves: Not surprisingly, this vegetarian recipe is very low-impact for the environment—it utilizes pantry staples like lentils and canned tomatoes (put up your own next summer!) and dried spices. Easy to make year-round, too.