Directions :

1. n a large pot, add chickpeas and enough water to cover. Stir in baking soda and soak at least 6 hours or overnight. Drain well and rinse until the water runs clear.
2. Return the chickpeas to the pot. Add 6 cups cold water, then bring to a boil over medium-high heat.
3. Reduce heat to medium and simmer until the dal is cooked and softened, about 30 minutes to 40 minutes. Skim any foam off the top of the water with a spoon. Add more water to cover as needed. Drain well.
4. Meanwhile, in a large saucepan over medium-high heat, heat oil until shimmering. Add cumin seeds and onion and stir until the seeds crack and pop and onion is softened, about 10 to 15 minutes.
5. Stir in garlic, garam masala, chili powder, and salt to taste (I like 1 teaspoon) until fragrant, about 1 minute. Stir in cooked dal, then add water to thin if desired (I added 1 cup water).
6. To make the tadka (see note 4):
7. In a small frying pan over medium heat, heat oil until shimmering. Add mustard seeds and cumin seeds and stir until they crack and pop. Stir in tomatoes, garlic, and chilies until fragrant, about 1 minute (WARNING: If your skillet is too hot, the pan may flame when you add the tomatoes, so keep a lid nearby).
8. When the garlic starts to turn golden, remove the pan from heat and drizzle over the dal. Garnish with fresh cilantro. Serve with cooked rice and pickled vegetables, if desired.