Heat vegetable oil in a large skillet over medium-high heat. Saute onion and garlic in hot oil until onion is translucent, 5 to 7 minutes.
Stir tomatoes with green chile peppers into the onion mixture; cook until the tomatoes darken in color, about 8 minutes; add ginger and cook until ginger is fragrant, about 2 minutes more.
Stir chickpeas, black tea, lemon juice, salt, cumin, garam masala, and coriander into the tomato mixture; bring to a simmer, reduce heat to medium-low, loosely cover the skillet, and cook at a simmer, stirring occasionally, until the tea has nearly evaporated completely, 15 to 20 minutes. Garnish with parsley.