Chop your onions and set aside.
Break your chicken into leg quarters and breasts. Place them in the Instant Pot with one cup of chopped onion, garlic, taco seasoning and one can of enchilada sauce. Add a half a can of water to the mix and stir.
Set the Instant Pot to cook for 20 minutes on high pressure.
While you are waiting for the chicken to cook, chop your tomatoes, lettuce, cilantro.
When the chicken is done cooking you can release the pressure manually or you can wait for it to release on its own. When you can open it, separate the chicken from the broth. Leave the broth in the Instant Pot and turn it on to sauté and reduce the liquid by half.
When the chicken has cooled enough to handle remove the bones and shred.
When the liquid has reduced combine it with the shredded cheese.
Turn your broiler on to Medium