Add onion, celery, chicken, and 1 cup of the water to the pressure cooker.
Cook on high pressure for 3 minutes (if using chicken breasts) or 8 minutes (for thighs).
Quick release the pressure.
Add sausage, rice, bouillon, and the remaining ⅓ cup water. Stir gently.
Cook on high pressure for 0 minutes.
Let pressure release naturally for 10 minutes, then quick release any remaining pressure.
Remove chicken, shred it, and return it to the pot. Stir to combine.
Season with salt and pepper to taste. Serve hot.
Notes
Long grain white rice works best. Avoid parboiled or quick-cooking varieties.The texture thickens as it sits—leftovers are excellent.For deeper flavor, you can sauté the sausage before step 1.