This is hands down my husband’s favorite Beef Stroganoff, and for good reason! It’s rich, creamy, and loaded with tender beef simmered in a savory, creamy sauce.
Heat the olive oil in a large Dutch oven or pot over medium-high heat. Working in batches, sear the meat until browned on each side, usually a couple of minutes per side.
Reduce the heat to medium-low and add the butter. Once melted, add the onions and cook for about 2-4 minutes. Add a pinch of salt, along with the garlic and cook for 30 seconds.
Cover with a lid, and allow to simmer on low for 2 hours. You can give it a stir once or twice while it cooks to check in on it, making sure nothing is sticking to the bottom.
Once the beef is tender, in a bowl, whisk together the sour cream, 1/4 cup of the hot liquid from the beef, and cornstarch/flour to thicken. Whisk well.