How to Make It
Place celery, carrots, onion, and thyme sprigs in the bottom of an electric pressure cooker. Sprinkle inside and outside of chicken with salt and pepper, and place on vegetable mixture. Seal pressure cooker lid, and bring to high pressure. Cook 25 minutes.
Carefully release pressure, and remove lid. Transfer chicken to a cutting board, and cut or shred into large pieces. Remove and discard thyme sprigs. Serve chicken immediately with vegetables and accumulated juices. If saving chicken for use in a different recipe, pour accumulated juices through a fine wire-mesh strainer into a bowl. Discard solids. Cool broth, and store in an airtight container in refrigerator.