Press "saute" button. Add 1 tbsp. olive oil and add the diced onion, garlic and jalapeno. Saute until onions are tender, about 4 minutes.
Press the "warm/cancel" button to turn saute function off. Now add in the chicken broth, chicken breasts, oregano, chili powder, cumin, salt, pepper, diced tomatoes.
Close the top of the instant pot. Press the "soup" button and let cook until cooking time is completed (30 minutes), then manually release pressure by flipping the vent at the top.
When done releasing pressure, open and using tongs, remove the chicken onto a cutting board and shred the chicken using two forks. It should shred extremely easily. Place shredded chicken back into the instant pot.
Add in the cilantro and the lime juice.
Place 1/2 an avocado, cubed, in the bottom of a soup bowl. Ladle soup over avocado. Enjoy!