Flat Iron Steak with a Creamy Mushroom Sauce

Preheat the oven to 325°F (165°C).

Season both sides of the flat iron steak with salt, pepper, garlic powder, and onion powder. Heat a large, oven-safe skillet over medium-high heat. Add 2 teaspoons of vegetable oil and heat until shimmering. Sear the steak on both sides for about 3 minutes each, until browned. Remove the steak from the skillet and reduce heat to medium.

Add the remaining 1 teaspoon of vegetable oil to the skillet. Add the mushrooms and cook for 10 minutes, stirring occasionally, until browned and softened. Lower the heat to medium-low, then pour in the wine and bring to a boil. Let it cook for 3 to 5 minutes until the wine reduces slightly, then add beef stock and bring to a simmer.

In a small bowl, mash the butter and flour together into a smooth paste. Stir this paste into the mushroom mixture and cook for another 5 minutes until the sauce thickens. Return the steak to the skillet.

Place the skillet in the preheated oven and cook the steak for about 10 minutes, or until it is just pink in the center. Slice the steak thinly against the grain and arrange it on a serving platter.

Stir in the cream with the mushroom sauce and heat for 1 to 2 minutes. Pour the sauce over the sliced steak and garnish with freshly chopped chives.