Set instant pot to sauté mode, medium heat. Once hot, add the olive oil and onion directly to the bowl of the Instant Pot and cook, stirring often, for 5-6 minutes, or until softened. Add the red bell pepper and continue to cook for an additional 2-3 minutes. Add the garlic, and cook, stirring continuously, for an additional 30 seconds.
Add the corn kernels, tomatoes, corn tortilla, taco seasoning, and enchilada sauce. Mix well to combine and continue to cook for an additional minute or so before adding the chicken breasts and water (or chicken stock) to the pot.
Cancel Sauté mode. Place the lid on your Instant Pot until it is secured properly (mine plays a little song for me). Select soup mode and set the timer to 6 minutes with a natural release (it takes approximately 10 minutes for your Instant Pot to reach pressure before the 6-minute countdown and another 10 minutes or so to naturally release pressure).
As the soup cooks, prepare the toppings and prepare the Baked Cinnamon Sugar Tortilla Strips (recipe below).
Once the soup is finished cooking, carefully remove the chicken breasts from the pot and transfer to a clean plate to cool just enough to handle. Meanwhile, add the canned black beans, green onions, and cilantro to the soup. Mix well to combine.
Season the soup with additional salt and pepper, to taste. If necessary, add a couple of teaspoons of sugar to help balance any acidity or bitterness.
Shred the chicken with two forks and return back to the pot. Mix well to combine.