Set Instant Pot to “Sauté” and adjust to “more”. Add butter. Once melted, add beef and onions and sauté, stirring occasionally, until the meat is browned, about 5 minutes. Add cinnamon, salt, pepper, and nutmeg and cook for another minute or two, stirring constantly, until well combined and fragrant. Stir in celery and parsley, then add water.

Close the lid, adjust the vent to “sealing” and set the Instant Pot to “Manual” high pressure for 20 minutes. Once the timer goes off, let the pressure release naturally.

Open the lid, and stir in 2 tablespoons lemon juice. Taste for seasoning and add more salt and lemon juice as needed.

Serve stew on top of basmati rice (I made one with dried dill stirred in) with as much of the liquid as you like spooned over top. Garnish with a sprinkling of ground sumac, a few spoonfuls of mast-o-khiar, and a sprinkling of parsley if desired.