Saute Aromatics & Seasonings: Set the Instant Pot on SAUTE function and set it on HIGH heat. Add oil and when the oil becomes moderately hot gently release the onion & garlic and saute until the onion becomes limp. Add salt to quicken the process. Now, add the seasonings and saute for just 30 seconds.
De-glaze Pot: Add the chicken stock and de-glaze the pot very well scraping the sides & the bottom of the pot with the help of a spatula. This is to loosen any stuck food particles from the bottom of the pot. This will prevent the BURN error. So, DO NOT rush this step.
Add Sauces & Chicken: Now, add the enchilada sauce and the tomato sauce. Give everything a good mix and than add the frozen chicken directly into the pot. No need to thaw! You can also use fresh chicken, but the cook time will change! Check time below.
Pressure Cook: CANCEL the SAUTE function. Secure the lid, seal the valve and PRESSURE COOK on HIGH for 10 mins (frozen chicken) and 5 mins for fresh chicken. Once, the pressure cooking cycle is over the instant pot will begin to beep, wait for 5 mins Natural pressure release (NPR) & than release the rest of the pressure manually by moving the valve from the sealing to the venting position.
Shred chicken: Open the lid carefully. Fish out the cooked chicken breasts and shred them with the help of a pair of fork. Set them aside.
Prep Masa Harina: Now, take the Masa Harina in a large enough bowl and add enough hot soup from the pot to the bowl. Whisk immediately until the Masa reaches a smooth and almost a lump free consistency. This will take some time.
Thicken Soup: Hit the SAUTE function & set it on LOW heat. Now, add the Masa paste in 2-3 slots stirring vigorously every time. It should completely blend well into the soup. DO NOT stop stirring briskly otherwise the paste will form lumps. Simmer the soup stirring frequently until it thicken to your desired consistency.
Add dairy & Chicken: TURN OFF the Instant Pot. Add the slightly warmed up heavy whipping cream into the soup. Mix well. Add the shredded cheddar cheese in 2-3 slots and mix well until the cheese completely melts and incorporates into the soup. You will have a pretty thick and smooth soup base. Finally, transfer back the shredded chicken into the pot. Mix well.
Serve with toppings: Serve the Chili's copycat Chicken Enchilada soup with your favorite toppings. We used some chopped yellow onion, jalapeno, roma tomatoes, cilantro, lime, tortilla chips and shredded cheddar as toppings.