In a large Ziplock Bag, toss togther flour, salt and pepper and stew meat until evenly coated.
Set your Instant Pot to Sauté setting and add butter. Add beef and cook for about 3-5 minutes until beef is browned on each side.
Add onion and garlic and cook for about 2 more minutes. Scoop out beef with slotted spoon and set aside.
Add beef broth and worchester sauce.Then, de-glaze pan (scrape with a wisk to get all of the browned bits off).
Add beef back in.
Place the lid on the Instant Pot. Select the "Meat/Stew" setting on the Instant Pot and set the timer for 35 minutes. Make sure the pressure release valve is in the sealing position.
When done, quick release the pressure valve, open up the lid carefully, and add sour cream, spicy mustard, and mushrooms.
Stir and let it simmer for about 10 minutes or until the mushrooms are cooked through. Add more salt, pepper to taste. If desired thicken the sauce with a little corn starch slurry or flour mixed with water.
Serve over prepared noodles or potatoes.
Steering Away From Traditional Stews
Traditional beef stew requires hours of slow simmering to tenderize tough cuts of chuck, but pressure cooking alters that timeline drastically. Unlike a classic pot roast that demands three hours in the oven, this adaptation harnesses sealed steam to break down connective tissue in under an hour. Sealing the meat in flour beforehand accomplishes two goals simultaneously: it protects the protein strands from drying out and builds the foundation for a starch-thickened sauce.
Mastering the Sauté and Deglaze Sequence
Searing meat directly in the stainless steel insert requires constant attention to prevent scorching. Browning the pieces for three to five minutes develops the Maillard reaction needed for deep flavor development. Scraping the bottom with a whisk during the deglazing phase removes all stuck fond. Leaving those browned bits attached will trigger the machine's burn warning on modern pressure cookers.
Managing Scaled Portions and Dairy
Adapting this recipe for larger or smaller crowds requires careful adjustment of the liquid ratios. Doubling the beef broth will not require a doubled pressure cooking time, since the thermal mass increases rather than the required chemical breakdown time. Stirring in the dairy after the pressure cycle prevents curdling. High heat denatures casein proteins rapidly, so sour cream must be introduced only during the final simmering phase over low heat.