One of the first things I learned when I began using a slow cooker was to avoid dairy, or at the very least, wait to add it at the end of cooking since it would curdle or separate if cooked for a longer period of time. Which is why I was surprised to find a recipe in Neela Paniz's cookbook, The Indian Slow Cooker, for yogurt soup.
Not only did I find the concept of a hot yogurt soup intriguing, but I was also interested in the fact that it could be done in the slow cooker at all. What prevents it from breaking? How does the tang of yogurt hold up over time? I went straight to the source for the answers.
"The recipes in the cookbook don't make any shortcuts," says Neela. "And this yogurt soup shows off what a slow cooker can do for Indian food beyond a dal or curry. But you have to follow the recipe for it to work."
Cooking with Yogurt
The key is to go full-fat. Fat acts like a buffer around the proteins in yogurt, making it less likely for it to curdle when exposed to heat, in comparison to 2 percent or fat-free options.
Starch Keeps Things Together
The sifted chickpea flour that's whisked into the soup does more than provide body, texture, and a lightly nutty flavor. It works as a binder, keeping the fat and water in the yogurt emulsified. It melts into the soup and won't leave a gritty texture.
Low and Gentle Heat
This recipes does the majority of its cooking on the low setting. High heat agitates the proteins in the yogurt and will cause them to seize up. The low, steady heat of the slow cooker actually makes what would otherwise be a fussy recipe achievable, thanks to the consistency of the heat.
The soup itself is inspired by kadhi,a type of yogurt curry, and contains a flicker of heat, thanks to a whole dried red árbol chile. Each spoonful of soup gives a glimpse of one or two spices used to season this dish — one slurp and your nose fills with earthy cumin; the next, the tang of the yogurt reveals slightly mentholated black cardamom. By the time you finish a bowl of this soup, you will have tasted every spice that went into it.
Yogurt Soup with Daikon
Serves 6 to 8
For the tadka:
1 1/2 tablespoons canola oil
1/2 teaspoon mustard seeds
1/2 teaspoon cumin seeds
1 whole dried red árbol chile, broken
1 (1-inch) piece cassia, broken
2 black cardamom pods
5 or 6 kari or curry leaves
For the soup:
2 1/2 cups full-fat plain yogurt, store-bought or homemade, at room temperature
5 cups water
3 tablespoons chickpea flour
1/8 teaspoon turmeric
1/4 teaspoon ground
Indian red chile or árbole chile
1 1/2 teaspoons salt
1 tablespoon sugar
1 medium daikon, peeled and cut into thin 1 1/2-inch-long sticks
Before prepping the ingredients, turn the slow cooker on to the high setting for 15 minutes, until the insert is warmed through. To make the tadka, heat the oil on high in a small saucepan, with a lid handy. Tilt the oil to form a pool and add the asafetida and mustard seeds; cover immediately to avoid splattering. When the sputtering of the seeds subsides, add the cumin seeds and then the chile, cassia, cardamom, cloves, and kari leaves. Add to the heated slow cooker insert.
To make the soup, in a bowl, whisk the yogurt with the water. Sift the chickpea flour into it and blend again. Add the turmeric, red chile, salt, and sugar. Mix well and add to the slow cooker. Reduce the heat to low and cook for 5 hours. Add the daikon and continue to cook for another half an hour (no longer, or the daikon will overcook).
You can remove the cassia, cardamom, and cloves before serving.
Reprinted with permission from The New Indian Slow Cooker by Neela Paniz, copyright (c) 2014. Published by Ten Speed Press.
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(Image credits: Karla Conrad; Eva Kolenko)