Start by rinsing the dried chickpeas under cold water. Place them in a large bowl, cover with water, and add the baking soda. Let them soak overnight or for at least 8 hours.
After soaking, drain and rinse the chickpeas. In a large pot or pressure cooker, add the chickpeas and cover with fresh water. Cook at high pressure for about 10-15 minutes in a pressure cooker, or boil and simmer for 1-1.5 hours in a regular pot until tender. Drain and set aside.
In a large skillet, heat the vegetable oil over medium heat. Add the sliced onions and sauté until golden brown, about 8-10 minutes. Stir in the cumin seeds, ginger, garlic, and minced green chili, cooking for another 2-3 minutes until fragrant.
Add the whole plum tomatoes (with juice) and tomato paste to the skillet. Break the tomatoes apart and stir in the garam masala, ground cumin, red chili powder, ground turmeric, and salt. Simmer for about 10 minutes.
Add the cooked chickpeas to the tomato mixture, stirring to combine. If the mixture is too thick, add a bit of water. Allow to simmer for an additional 10-15 minutes, stirring occasionally.
Remove from heat and garnish with fresh cilantro leaves and additional green chilies if desired. Serve hot with naan bread, grape tomatoes, and sliced red onion on the side.
