Season beef pieces generously with salt and pepper on all sides. Press the Sauté button on your Instant Pot and heat olive oil until shimmering.

Working in batches to avoid overcrowding, sear beef pieces for 3-4 minutes per side until golden brown. Transfer to a plate and set aside.

Add diced onion to the pot and cook for 3-4 minutes until softened. Add garlic and tomato paste, cooking for another minute until fragrant.

Pour in red wine to deglaze, scraping up any browned bits from the bottom. Let wine simmer for 2-3 minutes to cook off some alcohol.

Return seared beef to the pot along with beef broth, Worcestershire sauce, thyme sprigs, and bay leaves. Add potatoes, carrots, and celery.

Secure the Instant Pot lid and set valve to sealing. Cook on High Pressure (Manual/Pressure Cook) for 35 minutes.

When cooking is complete, allow for 10 minutes natural pressure release, then manually release remaining pressure.

Remove lid and discard thyme sprigs and bay leaves. In a small bowl, whisk flour with cold water to create a slurry.

Press Sauté button again and stir in flour slurry. Simmer for 3-5 minutes until stew thickens to desired consistency.

Taste and adjust seasoning with salt and pepper. Serve hot, garnished with fresh parsley.