Dice up the onion into ¼-½" dice. Slice 1 stalk of celery and 2 carrots into about ¼-½" slice. Peel and smash garlic cloves. Rinse the baby lima beans and remove any that are discolored, along with any stones or other debris.
Add the ham bone to the inner pot and add the bay leaf, water, ham juices, vegetables, garlic and thyme. Add the lima beans and stir so they are under the liquid.
Put the pressure lid on and turn the valve to seal. Set the pressure on high for 45 minutes. Allow the pot to natural release for 5 minutes and then manually release the remaining pressure. Remove the lid carefully. Taste the broth and adjust seasonings as needed.
While the soup is pressure cooking, thinly slice the remaining celery stalk and 2 carrots.
Remove the ham bone and set it on a cutting board. Add in the sliced vegetables and turn on the sear/sauté on high to cook the celery and carrots.
When the ham bone is cool enough to handle, remove the meat and chop it into bite size pieces. Return the ham to the pot. Serve and Enjoy!
If you don't have a ham bone, use a ham base and 1 pound of ham meat. I recommend Minors Ham Base and you can find the link in the post. I would use 1 tsp per cup of water and you will need 5 cups of water. You can always add more after the pressure cooking time if needed. If you have a ham bone, but don't have juices, use 5 cups of water and about 2 tsp of ham base. If your ham bone doesn't have at least 1 pound of meat on it, use extra ham.