2 pounds Yukon Gold potatoes, peeled, halved, and cut into 1/2-inch pieces
3/4 cup heavy cream
6 tablespoons (3/4 stick) unsalted butter, softened
Ground black pepper
1/4 cup crumbled Maytag blue cheese
3 tablespoons olive oil
8 (4-ounce) filets mignons, at least 1 inch thick
Salt and ground black pepper
4 ounces white mushrooms, sliced 1/8 inch thick
3/4 cup low-sodium beef broth
3/4 cup low-sodium chicken broth
1/2 cup dry red wine
1 tablespoon honey
2 tablespoons balsamic vinegar
1. For the potatoes: Bring the potatoes, 1 teaspoon salt, and enough water to cover the potatoes by 1 inch to a boil in a large saucepan over high heat. Reduce the heat to medium-low and simmer until a paring knife can be slipped into and out of the center of the potatoes with very little resistance, 10 to 13 minutes. Drain thoroughly.
2. For the tournedos: Meanwhile, heat 2 tablespoons of the olive oil in a 12-inch skillet over high heat until smoking. Season the beef with salt and pepper to taste. Place the beef in the skillet and cook without disturbing until well browned on the first side, about 3 minutes. Using tongs, flip the steaks and cook for 2 minutes longer for rare, 3 minutes for medium-rare, and 4 minutes for medium. Transfer the beef to a platter and cover with foil to keep warm.
3. Reduce the heat to medium-high and heat the remaining 1 tablespoon olive oil until shimmering. Add the mushrooms and cook, stirring frequently, until tender and golden, about 2 minutes. Transfer to a medium bowl and set aside.
4. Add the broths, wine, and honey to the pan and bring to a boil, scraping up the browned bits on the pan bottom using a wooden spoon. Boil until the liquid is reduced to 1 cup, 5 to 6 minutes. Stir in the vinegar and any accumulated juices from the steaks and cook for 1 minute to allow the flavors to blend. Add the mushrooms to the sauce and remove from the heat. Season with salt and pepper to taste and transfer to a liquid measuring cup; cover with plastic wrap to keep warm.
5. To finish the potatoes: Place a food mill or ricer over the now empty but still warm saucepan. Process or rice the potatoes into the saucepan. Stir in the cream and butter until smooth. Season with salt and pepper to taste. Rewarm if necessary.
6. Stir the blue cheese into the mashed potatoes, then divide the potatoes evenly among the centers of 4 warmed dinner plates. Place 2 tournedos, overlapping slightly, on top of the potatoes on each plate. Drizzle the pan sauce over the steaks and around the edge of the potatoes. Serve immediately.