Step 1

Cook the beef. In a large braiser or pan with straight sides, add the olive oil and butter and cook over medium-high heat to melt. Meanwhile, sprinkle the beef with salt and pepper. When the fat in the pan begins to swirl, add the beef and sear on all sides, getting good color, but not fully cooking, about 2 minutes per side. Remove with a slotted spoon to a plate.

Step 2

Make the sauce. In the same pan, add the mushrooms and cook until they are wilted and slightly darkened, 6 to 8 minutes. Add the onions, garlic and thyme. Season with a pinch of salt and more than a few grinds of black pepper. Cook, stirring constantly (to protect the garlic from browning), until the onions are tender, about 5 minutes. Sprinkle the flour evenly over the top and stir until the flour disappears. Continue to stir for a few more minutes.

Step 3

In a liquid measuring cup or bowl, whisk together the yogurt, horseradish and Worcestershire sauce. Slowly pour the beef stock into the yogurt mixture, whisking, making sure to whisk out any clumps. Pour this mixture over the sautéed vegetables in the pan. Reduce the heat to medium and cook, whisking constantly, until incorporated and thickened, 8 to 10 minutes. The sauce will break at first, but it will come together as it thickens and is whisked to emulsify. Add the seared beef back to the pan and stir.

Step 4

Prepare the noodles and serve. In a large bowl, toss the noodles with the parsley. Serve in shallow, wide bowls, with egg noodles on the bottom and topped with a scoop of the sauce and beef cubes. Garnish with a sprinkle of parsley.