Pepper. It's one of the top two condiments, in shakers on dining room tables across America, just waiting to make Aunt Mary's tuna casserole edible. It'll make you sneeze, and might make you pucker a bit. This classic dish celebrates the noir noshable by coating a juicy and tender steak with the seasoning. Classic mashed potatoes, augmented by roasted onion, rounds out the meal, along with mushrooms and sauce, all combining for perfect, rich bites that'll make your fork sing. Tell Aunt Mary we're sorry; we've got a new favorite pepper dish.
Halve and peel onion. Slice halves into thin strips.
Peel and cut potatoes into 1" chunks.
Pat steaks dry, and season both sides with ¼ tsp. salt. Season one side with coarse pepper.
Roast the Mushrooms and Onion
Place mushrooms on one side of prepared baking sheet and toss with 2 tsp. olive oil and a pinch of salt and pepper. Add onion to other side of baking sheet and toss with 1 tsp. olive oil and a pinch of salt.
Spread mushrooms and onion into single layers on their sides. (Some overlap with onion is ok.) Roast in hot oven until both are browned and softened, 28-32 minutes.
While mushrooms and onion roast, make mashed potatoes.
Make the Mashed Potatoes
Bring a medium pot with potatoes covered by lightly salted water to a boil. Cook until tender, 18-20 minutes.
Drain in a colander and return to pot. Add sour cream, ⅔ the butter (reserve remaining for sauce), and ¼ tsp. salt. Mash until smooth.
Cover and set aside.
While potatoes cook, cook steaks.
Cook the Steaks
Place a medium non-stick pan over medium heat and add 2 tsp. olive oil. Place steaks in hot pan, peppered-side down. For a flavorful and crispy crust, make sure pan is fully preheated. Cook on one side, 5 minutes.
Flip, and cook until steaks reach a minimum internal temperature of 145 degrees, 4-6 minutes.
Remove steaks to a plate and tent with foil.
Wipe pan clean and reserve.
Make the Sauce
Return pan used to cook steaks to medium-high heat. Add demi-glace and ¼ cup water. Stir, then bring to a boil.
Boil 1 minute, then remove from burner. Swirl in remaining butter.
Plate dish as pictured on front of card, garnishing steak with sauce and potato with onions. Bon appétit!