In wide bowl, combine the flour, salt and pepper. Add the sliced steak and toss to thoroughly coat. Set aside.
In a large skillet, heat the butter over medium-high heat. Add the floured steak, and cook until no longer pink, 2-3 minutes. Remove steak to a plate and set aside.
Add the diced onion to the skillet and cook 1-2 minutes, until onion starts to soften and turn translucent.
Add the garlic and cook 1 minute more. Add the mushrooms, broth, tomato paste and paprika, and cook for 2 minutes, until the sauce starts to thicken. Return the cooked steak to the skillet and heat through.
Remove from heat and add the yogurt or sour cream. Serve hot over cooked egg noodles, and garnish with chopped chives.