Combine carrots, bell pepper, onion and jalapeño pepper in a 6-quart Instant Pot. Add ½ cup water. Cover and seal. Cook on manual setting for 10 minutes. Quick release the pressure. Let cool slightly, and use an immersion blender to blend until smooth.
Stir in broth, diced tomatoes, tomato paste, garlic powder, black pepper, salt and cayenne pepper. Add chicken thighs. Cover and seal. Cook on manual setting for 13 minutes. Quick release the pressure and let cool slightly. Remove chicken and shred with two forks. Stir in peanut butter until blended, and add shredded chicken.
Serve over hot cooked rice, and garnish with chopped peanuts and cilantro, if desired.
This recipe makes a large amount but freezes great. Freeze leftover cooled soup in airtight containers for up to 3 months.