In pressure cooker pot, add chicken, salsa, chicken broth, onion, bell pepper, cumin, chilli powder, salt, pepper, cayenne pepper, and tomato paste. Stir together. Lock lid and set to high pressure for 10 minutes. When time is up, allow pressure to naturally release for 10 minutes and then use a quick release to get all the remaining pressure out. Remove lid and shred chicken using two forks. Set pressure cooker to simmer setting and add black beans and corn. Stir until corn is heated through. Ladle into bowls and tops with a squeeze of lime juice, a dollop of sour cream , a few sprigs of cilantro, chopped green onion, chopped avocado, and crushed tortilla chips.