Set the Instant Pot to the Sauté setting and add the olive oil, fresh thyme, salt, pepper, pieces of celery, chopped onion.
Cover with a basic lid and sweat the onions, stirring occasionally. Once cooked through, remove the lid and let the onions brown for just 1 minute before quickly pouring in the 2 cups of water.
Carefully add the trivet and get ready to place the chicken in the pot, breast side up. Double check that all packaging has been removed from the chicken and everything inside of the cavity has been removed.
Place sliced lemons inside or around the chicken.
Sprinkle with a little more salt, pepper, thyme and onions.
Twist on the locking lid, make sure the steam valve is set to sealing. Cancel the Sauté setting and select Manual or Pressure Cook on High. You want to cook the chicken for about 5.5 minutes per pound, so a 5lbs chicken would cook for 27 minutes. You can go as low as 5 minutes or as long as 6 minutes per pound with pretty good results.
Once the cook time has ended and the IP has beeped, let it natural pressure release for 25 minutes before removing the lid.
Remove the chicken by carefully lifting out the trivet and setting it right down onto a large plate or into an 8×8 baking dish. Let it rest while you filter the liquid left in the pot. You’ll want to save this! It is a type of super broth called bone broth, and because of the way the chicken cooks here, collagen is pulled from the skin and bones in particular and is perfect for sipping or cooking with! I strain it and then we either drink it with dinner or will freeze it in an ice cube tray to use late.