Dice the onion and mince the garlic. Pat the chuck roast dry and season both sides generously with salt and pepper.

Set the Instant Pot to Sauté mode and melt 2 tablespoons of butter.

Add the chuck roast and sear for 3 to 4 minutes on each side. Transfer the roast to a cutting board.

Pour the red wine vinegar into the pot. Scrape the bottom with a wooden spoon to loosen all the browned bits.

Add the remaining 2 tablespoons of butter, diced onion, garlic, and mushrooms. Sauté for 3 to 4 minutes, or until the onion is soft.

While the vegetables cook, slice the roast into small strips.

Whisk the flour into 1 cup of the beef broth until smooth.

Return the beef to the Instant Pot. Add the flour mixture, remaining beef broth, Dijon mustard, and Worcestershire sauce. Stir gently.

Secure the lid and set the valve to Sealing. Cook on Manual High Pressure for 7 minutes.

When the cooking time ends, carefully perform a quick release. Remove the lid after the pressure pin drops.

Stir in the heavy cream. Add the uncooked egg noodles and gently press them beneath the liquid.

Replace the lid and cook on Manual High Pressure for 3 minutes. Perform an immediate quick release when the cooking time ends.

Place the sour cream in a separate bowl. Add 1 cup of hot liquid from the Instant Pot and whisk until smooth.

Pour the sour cream mixture back into the pot and gently stir until everything is creamy and well combined.

Season with additional salt and pepper if needed. Garnish with fresh parsley and serve warm.