Heat the olive oil in a large stockpot or Dutch oven over medium-high heat.
Add the onion and cook until translucent and beginning to brown, 3–5 minutes.
Add the garlic, ginger, and green chile and continue to cook over medium heat until the garlic is fragrant and the chile is tender, 3–4 minutes.
Add the garam masala, turmeric, salt, and black pepper, then continue to cook for 1–2 minutes.
Add the tomatoes, chickpeas, and water. Stir to incorporate, using the spoon to scrape up any browned bits from the bottom and sides of the pot. As the tomatoes break down, the mixture should take on the consistency of a thick stew. Add more water if needed before bringing everything to a simmer, then cover with the lid and cook, stirring occasionally, for 15 minutes.
Remove the lid, reduce the heat to low, and stir in the lemon juice and cilantro. Cook for 1–2 minutes, until the cilantro has wilted and turned bright green.
Serve over basmati rice or with a side of naan.
