Step 1

Heat 1 tablespoon oil in Dutch oven over medium-high heat until shimmering. Add mushrooms and 1/4 teaspoon salt and cook until liquid has evaporated and mushrooms begin to brown, 5 to 7 minutes; transfer to bowl.

Step 2

Add remaining 1 tablespoon oil to now-empty pot and return to medium-high heat until shimmering. Add onion, garlic, 1/2 teaspoon salt, and 1/2 teaspoon pepper and cook, stirring occasionally, until onion begins to soften, about 5 minutes. Add beef, 1/4 teaspoon salt, and 1/4 teaspoon pepper and cook, breaking up meat with spoon, until no longer pink, 5 to 7 minutes.

Step 3

Add flour and stir until beef is well coated; cook for 1 minute. Stir in broth and wine and bring to simmer, scraping up any browned bits. Cook until mixture is slightly thickened, about 3 minutes. Stir in noodles, reduce heat to medium, and cook, uncovered, until noodles are tender, 10 to 12 minutes, stirring occasionally.

Step 4

Off heat, stir in sour cream and mushrooms until fully combined. Season with salt and pepper to taste. Transfer to shallow platter and sprinkle with chives. Serve, passing extra sour cream separately.