Melt the butter in a large skillet over medium heat. Add the chopped onion and half of the salt. Cook until the onion becomes soft, translucent, and lightly golden around the edges.
Add the tomato paste to the skillet and stir continuously. Cook for several minutes until the paste darkens slightly and develops a deeper flavor.
Stir in the drained chickpeas, baking soda, garam masala, cumin, and Kashmiri chili powder. Mix thoroughly so every chickpea gets coated in the flavorful spice mixture.
Pour in the heavy cream and water. Stir well to combine all ingredients into a smooth sauce. Bring the mixture to a gentle simmer while stirring occasionally.
Allow the curry to simmer for about 10 to 15 minutes. The sauce will thicken, and the chickpeas will become tender while absorbing all the wonderful flavors.
Taste and adjust seasoning if necessary. Sprinkle fresh cilantro over the top before serving. Enjoy with warm basmati rice or soft naan bread.