Optional: chopped avocado, jalapeno, and lime wedges
Select saute setting on a 6-qt. electric pressure cooker and adjust for high heat; add oil. Add onion; cook and stir 6-8 minutes or until tender. Add garlic; cook 1 minute longer. Add remaining ingredients, except cilantro. Stir. Lock lid; close pressure-release valve.
Adjust to pressure-cook on high for 8 minutes. Allow pressure to naturally release for 12 minutes, then quick-release any remaining pressure.
Remove chicken from the pressure cooker. Shred with 2 forks; return to pressure cooker. Stir in cilantro. If desired, serve with toppings.