Heat oil in a large pot or Dutch oven over medium heat.

Add cumin seeds and diced onions to the hot oil.

Cook for approximately 3 minutes, or until the onions are translucent and softened.

Add the crushed garlic and grated ginger to the pot.

Cook for another 5 minutes on low heat, stirring occasionally to prevent burning, until fragrant.

Stir in turmeric powder, cayenne pepper, coriander, and salt.

Add the chopped tomatoes and garam masala.

Cook on low heat for 10 minutes, stirring occasionally, allowing the tomatoes to break down and the flavors to meld.

Add the cooked chickpeas and lemon juice to the pot.

Stir to combine, then cook for 5 minutes to heat the chickpeas through.

Add the boiled, peeled, and chopped potatoes.

Simmer for another few minutes until the potatoes are heated through.

Serve hot over white steamed basmati rice.

Garnish with chopped green jalapeno peppers, if desired.