Black Chana with Potato

Step 1
Sort and clean chickpeas and wash them under cold water; drain. Combine chickpeas, 1/2 teaspoon salt, and baking soda in a large bowl; add 1 quart water. Soak chickpeas for 24 hours; drain.

Step 2
Combine onion, garlic, and ginger in a blender; add 3 tablespoons water. Blend mixture at high speed until a smooth paste forms.

Step 3
Heat oil in a 4-quart pot over medium-high heat. Add cumin seeds and asafoetida; cook and stir until asafoetida expands and cumin seeds darken, about 1 minute. Stir in onion paste, taking great care to avoid splattering. Cook and stir until well mixed and fragrant, about 5 minutes.

Step 4
Stir chickpeas, potatoes, remaining 1 teaspoon salt, coriander, garam masala, turmeric, and cayenne pepper into onion-cumin mixture; add 2 cups water. Bring to a boil and cover the pot; reduce heat and gently simmer for 1 hour.

Step 5
Stir in tamarind paste. Continue cooking, stirring occasionally, for 10 minutes more.