Wash and soak chickpeas for at least 8 hours. Drain and rinse.
Cook chickpeas in an Instant Pot with 2 cups of water for 25 minutes.
In a saucepan, heat oil and add gram flour. Stir-fry until golden brown.
Add grated ginger, minced green chili, and cooked chickpeas to the gram flour.
Season with salt, black salt, black pepper, roasted cumin powder, mango powder, and 1/2 cup water.
Mash chickpeas lightly and cook on low heat for 10-15 minutes.
Turn off heat and add garam masala and lemon juice. Let sit for at least 30 minutes.
Before serving, drizzle with tamarind chutney.