Sauté Aromatics: Turn the Instant Pot to Sauté mode and set it to High/More. Melt the butter in the pot, then add the diced onion, garlic, and ginger. Sauté for about 5 minutes, stirring occasionally, until the onion softens and starts to brown slightly.
Cook Chicken & Spices: Add the chicken to the pot and cook for about 2-3 minutes, until the edges start turning opaque but aren’t fully cooked. Sprinkle in paprika, 3 teaspoons of garam masala, cumin, turmeric, ½ teaspoon seasoned salt, and cayenne (if using). Stir well and sauté for another minute.
Add Tomatoes & Coconut Milk: Pour in the diced tomatoes (with their juices) and coconut milk. Top with Greek yogurt, but do not stir it in—just let it sit on top.
Pressure Cook: Secure the Instant Pot lid and set the valve to the Sealing position. Select Manual/Pressure Cook on High Pressure for 8 minutes. Once done, quick release the pressure.
Prepare Cornstarch Slurry: While the pressure releases, mix 2 tbsp cornstarch with 2 tbsp water in a small bowl to create a slurry. Set aside.
Final Sauce Enhancements: Open the lid and stir in tomato paste, heavy cream, the remaining teaspoon of garam masala, and the last teaspoon of seasoned salt. Set the Instant Pot to Sauté (More/High) and bring the mixture to a simmer. Stir in the cornstarch slurry and cook for 30 seconds until the sauce thickens. Turn off the Instant Pot and let the curry sit for 5 minutes.
Serve & Garnish: Spoon the creamy curry chicken into bowls and garnish with fresh cilantro. Serve hot with naan on the side.