Press the Saute function on instant pot and once its hot add in olive oil. Add onion, celery, carrots, and bay leave and saute until tender (about 5-7 minutes).
Add in garlic, rosemary, parsley (if using), salt. Saute another minute.
Add beans, stock, worcestershire sauce, and vinegar. Place on high pressure for 8 minutes and do a quick release.
Use an immersion blender or a masher to blend half the beans for a thicker consistancy.
Add chicken and kale to warm up for about 5 minutes. Add lemon juice. Garnish with parsley and fresh cracked black pepper if desired.