Cut the chicken into pieces. If using the Instant Pot, cut a chicken breast into 4, and thighs in half. If cooking in a slow cooker, cut the chicken into bite-sized pieces. I prefer roughly 1 1/2 x 1 1/2-inch chunks.
In a bowl large enough to hold the chicken pieces, mix the marination ingredients. Add the chicken and stir to coat well. For the Instant Pot method, the longer you marinate (up to 12 hours) the more flavorful the final result will be. Cover and place in the refrigerator. If you are using a slow cooker, there is no need to marinate the meat any longer than it takes to mix together the rest of the ingredients.
While the chicken is marinating, mix together the masala ingredients.
Cook in the Instant Pot
Layer the masala ingredients in the bottom of the inner lining of the Instant Pot. On top carefully lay the marinated chicken. Place the lid on, close the vent, and set to High Pressure for 9 minutes.
When the cooking time is finished, do a Quick Release. Open the lid and check for doneness (an internal temperature of 165°F (75°C). If not quite done, using the sauté function, cook for a couple of minutes until cooked through.
Stir in the cream, half and half, or coconut milk, and the dried fenugreek leaves, if using. If the sauce if not thick enough, remove the chicken and turn on the sauté function for 5 minutes, or until the sauce is the desired consistency. Add the chicken back into the pot and warm through. If the flavor is too intense add a bit more dairy or coconut milk. Garnish as you wish. Serve with rice, bread, a favorite vegetable dish, and some raita (or some plain yogurt would be perfect too).
Slow Cooker Instructions
Mix the marinated chicken and the masala ingredients and pour into the slow cooker.
Cook the chicken on high for 3 to 5 hours, or on low for 6 to 7 hours, or until the meat is cooked through. How long it will take depends on the size of the chicken pieces and your slow cooker, but start checking at the 3-hour mark. You are looking for an internal temperature of 165°F (75°C).
Stir in the cream (half and half or coconut milk) and the dried fenugreek leaves (if using). If the sauce if not thick enough, spoon out the chicken into a bowl, and pour the sauce into a saucepan. Cook over medium-high heat until it reaches the desired consistency. Add the chicken to the pan and heat through. Review the tasting and serving ideas listed above.
If you prefer using chicken breasts there are several things you can do to keep them from overcooking: leave the breasts whole, and reduce the High Pressure cook time to 8 minutes. Cut the chicken up before serving.
I am suggesting 3 optional ingredients which add a smoky flavor since you won’t be grilling the chicken for either of these cooking methods: mustard oil, smoked paprika, and liquid smoke. Use all or none depending on your preferences.
Kashmiri chili is not particularly spicy chili, but is used for flavor and the color it give a dish. If you are heat-shy or can't find Kashmiri chili, please read through my substitutions section on chilis; the link is above.
There is some overlap of ingredients between the marination spices and the masala. It may be efficient to measure both at the same time.
In order to streamline this recipe, I have skipped the blending step for the sauce. I find that if you use tomato purée and finely mince the onion, blending is not really necessary, but this is up to you.
If you want some browning on the chicken, after cooking, you could broil or sauté it in a pan on the stove-top. I skip this step, but you may do this for a smoother sauce.
I use a 6-quart Instant Pot. But in reading some feedback online, I see that when using the 8-quart Instant Pot, some people are getting a burn notice if making a recipe this size. You may consider doubling the amounts I've listed if you are using the larger model.
This Instant Pot chicken tikka masala freezes beautifully. If you have any leftover sauce, mix in leftover roast chicken, vegetables or anything else that sounds good to you.