Drain and rinse garbanzo beans.

Set aside.

Heat oil in a skillet over medium heat.

Add cumin and black mustard seeds.

Wait for the mustard seeds to stop popping.

Add chopped onion, minced green chili, and minced garlic.

Saute until the onion becomes translucent.

Add the drained garbanzo beans to the skillet.

Saute for 1 minute.

Add chopped tomatoes (with liquid), salt, turmeric, and chana masala.

Toss the seasonings with the beans.

Add approximately 1/2 cup of water to create a gravy.

Cook until the liquid thickens into a spicy gravy, about 5 minutes.

Before serving, top with butter and lemon juice (optional).

Serve immediately with rice or chapati.