Add the minced garlic and grated ginger. Cook for 1 minute until fragrant.
Add the chicken pieces, salt, turmeric, garam masala, cumin, coriander, and cayenne pepper. Stir well to coat the chicken with the spices. Cook for 3 minutes, stirring occasionally.
Stir in the crushed tomatoes and chicken broth. Scrape the bottom of the pot to remove any browned bits.
Secure the lid and set the vent to Sealing. Cook on Manual/Pressure Cook setting on High for 6 minutes.
When cooking is complete, allow a Natural Pressure Release (NPR) for 5 minutes, then carefully switch the valve to Venting for a Quick Release (QR) of any remaining pressure.
Open the lid. Stir in the butter pieces until melted.
In a small bowl, whisk together the cornstarch and water to create a slurry. Stir the slurry into the chicken mixture.