Usually I have made this soup on the stove top. I adventured out and made it in my Instant Pot. The best Split Pea soup I have eaten. I shouldn't be surprised - soups I have made in the past in my Instant Pot have come out great.
Try this recipe from The Country Cook and I don't believe you will be disappointed.
Instant Pot Split Pea Soup
2 stalks celery, chopped
2 carrots, chopped
1 1 leek, thinly sliced (white part only)
1 cup leftover chopped ham
1 ½ cups dried green split peas
2 cloves garlic, minced
½ tsp salt
½ tsp pepper
½ tsp liquid smoke
1 quart chicken broth
Wash and cut all the vegetables needed and chop ham. Sort and rinse the dried split peas. Look for any little hard bits that should be removed.
Add all the ingredients to the Instant Pot and stir.
Secure the lid in place and set the vent to sealing.
Cook on Manual high pressure for 15 minutes.
Carefully release the steam by doing a quick steam release.
Thin the soup with water if needed to bring it to the consistency you desire. The soup will continue to thicken as it cools.