Vegan Chickpea Curry without Coconut Milk

Drain and rinse chickpeas under cold running water. Place in a bowl, cover with cold water, and stir in baking soda. Soak for 10 minutes. Drain and rinse thoroughly. Heat oil in a pot and cook onion until soft and translucent, about 5 minutes. Stir in garlic-ginger paste, cayenne, salt, turmeric, and garam masala. Cook and stir until spices are well absorbed by the onion, about 2 minutes. Add tomatoes and frozen spinach; stir to combine. Add chickpeas and stir gently. Simmer until flavors are well combined, about 20 minutes. Add a little water if sauce is too thick.