Instant Pot Indian Butter Chicken

Ingredients

• 1 tablespoon olive oil or ghee
• 1/2 cup diced white, red or yellow onions
• 3-4 medium cloves garlic, finely minced or pressed through a garlic press (for about 2 teaspoons)
• 1/2 tablespoon grated fresh ginger or ginger paste (see note)
• 2 pounds boneless, skinless chicken breasts (see note if using chicken thighs), cut into about 1-inch pieces
• 2 cups peeled, chopped russet, yellow or red potatoes (about 10 ounces)
• 2 teaspoons ground coriander
• 2 teaspoons garam masala
• 2 teaspoons turmeric
• 1 teaspoon salt (I use coarse, kosher salt)
• 1/2 teaspoon paprika
• 2 cans (15-ounces each) canned tomato sauce
• 1 can (15-ounces) reduced fat coconut milk
• 1 to 2 tablespoons butter, optional (but delicious)
• Hot, cooked rice for serving
• Fresh, chopped cilantro, for garnish

Instructions

1. Add the oil to the insert of the Instant Pot and select the Saute function (making sure the temperature is adjusted, using the + or - button, to normal). Add the onions, and cook, stirring often, until they start to soften and turn translucent, 2-3 minutes. Add the garlic and ginger and cook for 10-20 seconds.
2. Add the chicken and cook, stirring often, 1-2 minutes.
3. Add the potatoes, spices (coriander, garam masala, turmeric, salt and paprika), tomato sauce, and coconut milk. Stir well.
4. Secure the lid and make sure the valve is closed. Select the Manual or Pressure Cook button and dial up or down to 6 minutes. The Instant Pot will start on it's own.
5. After the cooking time is finished, quick release the pressure (if it bubbles and spurts through the valve, close the valve, let it sit for 10 minutes and try again), and remove the lid.
6. Add the butter and give the curry a good stir to melt the butter completely (see note if you want to thicken it up a bit more). Serve over rice garnished with fresh cilantro, if desired.

Notes

For fresh ginger, I buy knobs of ginger, cut them into 1- or 2-inch pieces and toss in a freezer bag. When I need fresh ginger for a recipe, I grab a knob of ginger straight from the freezer and grate it on my microplane or on the small holes of my box grater (no need to thaw or peel the ginger before using). Ginger paste, which is pretty widely available these days in the refrigerated section of stores often by the fresh herbs, is a great option, too. 
For chicken thighs, add 5-6 minutes to the cooking time. 
The curry will thicken a little more as it cools. If you want it thicker for serving, mix together 1 tablespoon cornstarch with 2-3 tablespoons cold water. Turn the IP to the Saute function and add the cornstarch slurry, whisking constantly, until the mixture is thick and bubbling. 
Also, I haven't made this particular recipe in the slow cooker or on the stovetop, so I didn't include directions in the recipe, but having said that, I think it would transition well to both options (maybe simmer for 15-20 minutes on the stovetop and try cooking on low for 5-6 hours in the slow cooker).