3 tablespoons butter, divided
1 pound boneless skinless chicken thighs, cut into 2-inch cubes
1/2 teaspoon salt
1 white onion, peeled and small-diced
4 cloves garlic, minced
1 inch ginger root, peeled and grated
1 cardamom pod
1 teaspoon garam masala
1 teaspoon ground coriander
1 teaspoon ground turmeric
1/4 teaspoon cayenne pepper
8 ounces tomato passata
1/2 cup heavy cream
Heat 1 tablespoon of the butter in the Instant Pot on the sauté setting.
Add the chicken pieces in an even layer and season with salt. Cook for about 2 minutes per side, until browned. Remove and set aside on a plate.
Add the remaining butter to the Instant Pot and add the onion. Cook, stirring occasionally, until slightly browned, about 5 minutes.
Add the garlic, ginger and all of the spices to the Instant Pot. Cook for 1 minute, until just fragrant, and turn off the Instant Pot.
Add the chicken (and any juices that have accumulated on the plate) and the tomato passata to the Instant Pot. Cook on the meat setting for 8 minutes, and then release the pressure and remove the lid.
Remove the cardamom pod and stir the cream into the curry. Cook on the sauté setting for about 5 minutes or until the sauce achieves the desired thickness.