Sauté Aromatics: Set your Instant Pot to 'Sauté' mode. Once hot, add the coconut oil. Add diced onion and cook until softened, about 5-7 minutes. Stir in minced garlic and grated ginger, cooking for another minute until fragrant. If you're concerned about the 'burn' notice, ensure to deglaze the pot thoroughly after this step, scraping any browned bits from the bottom.
Add Spices and Tomatoes: Stir in the curry powder, cumin, coriander, turmeric, and cayenne pepper (if using). Cook for 30 seconds, stirring constantly, to bloom the spices. Pour in the diced tomatoes and their juices. Scrape the bottom of the pot really well with a wooden spoon to ensure no bits are stuck, which helps prevent the 'burn' notice, a common issue when making Instant Pot Chickpea Curry.
Layer Ingredients: Add the rinsed and drained canned chickpeas (or soaked dried chickpeas if using, adjust cook time accordingly for dried). Pour in the vegetable broth and the full-fat coconut milk. Do NOT stir at this point; layering helps prevent the burn notice by keeping thicker ingredients off the bottom.
Pressure Cook: Secure the lid and set the vent to 'Sealing'. Select 'Manual' or 'Pressure Cook' on High for 5 minutes for canned chickpeas (15-20 minutes for soaked dried chickpeas). Once cooking is complete, allow a Natural Pressure Release (NPR) for 10 minutes, then carefully quick release any remaining pressure.
Stir in Spinach and Thicken: Carefully remove the lid. Stir in the fresh spinach, allowing it to wilt into the hot curry for a minute or two. For a thicker Instant Pot Chickpea Curry, you can either continue to simmer on 'Sauté' for 5-10 minutes with the lid off, or mix 1 tablespoon of cornstarch with 1 tablespoon of water to create a slurry and stir it into the curry while on 'Sauté' mode until thickened to your desired consistency.
Finish and Serve: Stir in the garam masala. Taste and adjust seasonings as needed, adding more salt or spice if desired. Serve your delicious Instant Pot Chickpea Curry hot, garnished with fresh cilantro, alongside Basmati rice or warm naan bread.