French-Style Flank Steak with Mashed Potatoes

Marinate the meat

1. Using a knife, make cross-hatch incisions in the steak then place it into a dish. Add the olive oil, half of the shallots, herbs, and half of the wine. Season with pepper to taste. Let stand in the refrigerator at least 12 h (up to 24 h).

Grill outdoor or in the oven and prepare the vegetables

2. Preheat the oven to 195°C/375°F or an outdoor grill to 'medium'.
3. Prepare the potatoes, leaving the skin on. Boil or steam until very tender, about 20 -25 min. Drain well and peel. Clean the mushrooms. Set aside.
4. Take the steak out of the marinade. Drain the steak and pat it dry. Set the marinade aside. Put the steak on the rack of a broiler pan, or, alternatively, put the steak on a grill rack.
5. Cook in the middle of the oven or on a medium hot grill. The exact cooking time depends on the steak's thickness and on how you prefer it cooked. For a steak of 300 to 450 g, calculate 10-12 min for rare, 15-17 min for medium-rare. For a steak of 500-600 g, calculate about 15 min for rare, 18-20 for medium-rare. It is important not to overcook the flank steak since it will become tough if overcooked.
6. Meanwhile, in a microwave-safe bowl, pour in the milk with butter and microwave on medium-high for a couple tens of seconds until hot.
7. Pass the potatoes through a food mill, then put the purée back into the pot used to cook the potatoes. Pour in the butter-milk mixture. Add more or less milk depending on how creamy you like your purée. Season with salt and pepper to taste, then blend well using a spatula. Set aside.
8. Heat the canola oil in a saucepan over medium heat. Add the mushrooms and sauté, with stirring, until the mushrooms are browned and any liquid they give off has evaporated, 3-4 min. Lower the heat to medium-low, then stir in the remaining shallots and sauté until translucent, 2-3 min. Season with salt and pepper to taste. Set aside.
9. Transfer the steak to a cutting board, cover it loosely with aluminum foil, then let the meat stand for 5 minutes in order to reabsorb the meat juices.
10. Meanwhile, heat the reserved marinade in a small pan together with any remaining cooking juices. Pour in the rest of the wine and cook 1 min over high heat. Reheat the potatoes.
11. Cut the steak into serving size portions, add salt to taste, pour the sauce over the steak, then serve with the mushrooms, mashed potatoes and bread.