Pan-Seared New York Strip Steak with Mushroom Sauce, Creamy Mashed Potatoes and Roasted Carrots

This steak dinner is all about bold, meaty flavor paired with comforting sides. A perfectly seared New York strip steak is topped with a luscious mushroom pan sauce made with beef demi-glace and Dijon mustard. On the side, ultra-creamy mashed potatoes are elevated with caramelized onions, while roasted baby carrots add a touch of sweetness and color.

Every element comes together for a hearty, satisfying meal that feels special enough for a celebration but is simple enough for a weeknight. The key is building layers of flavor: browning the onions slowly, searing the steak to a perfect crust and finishing the sauce in the same pan to capture all those delicious browned bits.

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Ingredients

1 unit Yellow OnionView ingredient guideLike ingredientDislike ingredient

2 clove GarlicView ingredient guideLike ingredientDislike ingredient

8 ounce CarrotView ingredient guideLike ingredientDislike ingredient

4 ounce Button MushroomsView ingredient guideLike ingredientDislike ingredient

16 ounce Yukon Gold PotatoesView ingredient guideLike ingredientDislike ingredient

0.25 ounce ParsleyView ingredient guideLike ingredientDislike ingredient

6 tablespoon Sour CreamView ingredient guideLike ingredientDislike ingredient

12 ounce New York Strip SteakView ingredient guideLike ingredientDislike ingredient

1 unit Beef Demi-GlaceView ingredient guideLike ingredientDislike ingredient

1 teaspoon Dijon MustardView ingredient guideLike ingredientDislike ingredient

2 tablespoon Vegetable OilView ingredient guideLike ingredientDislike ingredient

2 tablespoon ButterView ingredient guideLike ingredientDislike ingredient

Salt, to tasteView ingredient guideLike ingredientDislike ingredient

Pepper, to tasteView ingredient guideLike ingredientDislike ingredient

Instructions

1. Preheat the oven to 425°F (220°C) with a rack in the upper position. Wash and dry all produce. Halve, peel and thinly slice the onion. Thinly slice or mince the garlic. Halve the carrots lengthwise through the stems. Trim and thinly slice the mushrooms. Peel the potatoes and cut them into ½-inch cubes. Pick the parsley leaves from the stems; discard the stems and finely chop the leaves.
2. On a baking sheet, toss the carrots with a large drizzle of vegetable oil and season with salt and pepper. Roast until tender and slightly charred at the edges, 20-25 minutes. Meanwhile, place the potatoes in a medium pot and add enough salted water to cover by 1 inch. Bring to a boil and cook until tender, about 15 minutes. Drain thoroughly.
3. Heat a large drizzle of oil in a medium pan (preferably nonstick) over medium-high heat. Add the onion and cook, stirring occasionally, until browned and very soft, about 15 minutes. Add a splash of water every now and then to scrape up any browned bits. Transfer the caramelized onions to a small bowl and season with salt and pepper.
4. Return the drained potatoes to the empty pot and place over low heat. Mash with a potato masher until smooth. Stir in the sour cream and season with salt and pepper. Keep warm over low heat. Wipe out the pan used for the onions, then heat a large drizzle of oil in it over medium-high heat. Pat the steak dry with a paper towel and season generously with salt and pepper. Add the steak to the pan and cook to your desired doneness, 3-6 minutes per side. Remove the steak from the pan and set aside.
5. Add 2 tablespoons of butter and the sliced mushrooms to the same pan over medium-high heat. Cook, tossing, until softened, 2-4 minutes. Add the garlic and cook until fragrant, about 1 minute. Stir in the beef demi-glace and ¼ cup of water, then bring to a boil. Reduce the heat to a simmer and stir in 1 teaspoon of Dijon mustard. Simmer until the sauce slightly thickens, 1-2 minutes. Remove from heat and stir in half of the chopped parsley. Season the sauce with salt and pepper.
6. Divide the mashed potatoes and roasted carrots between plates. Spoon the caramelized onions over the potatoes. Slice the steak against the grain and arrange on top of the potatoes and onions. Spoon the mushroom sauce over the steak, making sure to include the mushrooms. Garnish with the remaining parsley. Serve immediately.

Recipe Tips

FAQ

Can I use a different cut of steak?

Yes, you can substitute with ribeye or sirloin, but adjust cooking time based on thickness.

What can I use instead of sour cream in the mashed potatoes?

You can use plain Greek yogurt or heavy cream for a similar creamy texture.

How do I know when the steak is done?

Use a meat thermometer: 125°F for rare, 135°F for medium-rare, 145°F for medium and 160°F for well done.