Using the sauté function (set on high, if possible), heat 1 tablespoon of the oil in the pressure cooker pot. Add half the meat, spread it over the oil, and let it brown without stirring (this helps encourage browning) for 5 to 7 minutes. Give the meat a good stir and sauté for 1 more minute. Use a slotted spoon to transfer the meat to a plate and season with 1/2 teaspoon of the salt. Repeat with the remaining 1 tablespoon oil, meat, and another 1/2 teaspoon salt.
Stir the onion, bell pepper, diced chile, garlic, and ½ teaspoon of the salt into the pot and cook until softened, about 5 minutes.
Stir in the tomato paste, chili powder, oregano, and cumin and cook until fragrant, about 1 minute. Stir in the meat and any juices from the plate, along with the tomatoes, beans, and remaining ½ teaspoon salt.
Lock the lid into place and cook on high pressure for 8 minutes. Let the pressure release naturally.
Stir in the cilantro and a squeeze or two of lime juice, then taste and adjust the lime juice and salt if necessary. Serve with the sour cream and avocado (if using).
Slow-cooker variation: After step 3, slow cook on high for 2 to 3 hours or low for 4 to 5 hours.