Place broth, chicken, celery potatoes, carrots, onion, bay leaf, salt, and pepper inside the instant pot – select ‘’Manual” setting on “High” for 12 minutes. Carefully ‘Vent” and release the steam. Transfer chicken to a plate or bowl, and shred with 2 forks.

Preheat oven to 400°F. In a saucepan, melt butter – stirring often. Add flour; whisk constantly. Slowly add in the milk; until thickened. Pour milk mixture back into cooker; along with shredded chicken, peas, and a pinch of thyme; stir to combine.

Spoon chicken mixture into a 13- x 9-inch baking dish coated with cooking spray. Arrange biscuits over top of chicken mixture. Place baking dish on a rimmed baking sheet lined with aluminum foil. Bake in preheated oven until biscuits are golden brown and chicken mixture is thick and bubbly, about 30 minutes. Remove from oven, and let stand 10 minutes. Garnish with additional thyme before serving.