Season the cubed chicken with 1 teaspoon of kosher salt and set aside.
Set the Instant Pot to Sauté and add the ghee (or butter/coconut oil). When hot, add the chopped onion, minced garlic, and grated ginger and cook until softened, about 2–3 minutes.
Add the ground coriander, cumin, turmeric, garam masala, cayenne, and cardamom to the pot and sauté with the aromatics until the spices are fragrant, about 30 seconds.
Stir in the drained diced tomatoes and use an immersion blender to puree until mostly smooth (or transfer to a blender and puree, then return to the pot).
Add the seasoned chicken and the remaining 1/2 teaspoon kosher salt to the pot and stir to combine.
Lock the lid, set the Instant Pot to High Pressure, and cook for 15 minutes.
Perform a quick release of the pressure. Open the lid and add the cauliflower florets and frozen peas, then reseal and cook on High Pressure for 2 minutes.
Quick release the pressure again, open the lid, stir in the coconut milk, and adjust seasoning if needed.
Serve hot garnished with fresh cilantro leaves.