May Contain: Egg, Peanuts, Seafood, Sesame, Soy, Tree Nuts, Wheat, and Gluten.
- Turn oven to 425°F.
- Line a baking sheet with foil.
- Wash potatoes and cut into 1 inch pieces.
- Place potatoes on baking sheet and toss with 1 tbsp. (2 tbsp. for 4 servings) olive oil. Season with salt and pepper.
- Place in oven immediately and set a timer for 15 minutes.
- When timer goes off, toss potatoes with a spatula. Place potatoes back in oven for 10-12 minutes or until tender.
- Drain striploin steak and pat dry with a paper towel.
- Season with salt and cracked black pepper.
- Heat a large skillet over medium-high.
- Once hot, place steak in skillet fat side down and cook for 2 minutes.
- Turn steak and place flat side down. Sear 3-4 minutes until well browned.
- Flip steak and sear on opposite side for 3-4 minutes.
- Transfer steak fat side down to baking sheet with potatoes. Place baking sheet in oven and toast for 10-12 minutes, or until internal temperature reaches 135°F.
- Remove baking sheet from oven. Leave steak on cutting board to rest.
- To same skillet over medium-high, add 1 tbsp. (2 tbsp. for 4 servings) butter.
- Wash cremini mushrooms and slice thinly.
- Add mushrooms to skillet. Cook for 4-5 minutes, stirring often, until lightly browned.
- Add garlic and balsamic vinegar to skillet. Swirl sauce to coat mushrooms.
- Cook for 1 minute, or until vinegar is absorbed and garlic is fragrant.
- Season with salt and pepper to taste.
Prepare Steak Sauce
- In a small bowl, combine dijon mustard, grainy mustard, and horseradish.
- Season to taste with salt and pepper and set aside.
- Wash chives and finely slice.
Plate + Serve
- Divide potatoes onto dinner plates along with sauteed mushrooms.
- Cut steak against the grain into 1/4 inch slices.
- Divide steak onto plates and garnish with chives.
- Serve with prepared steak sauce.