Filet Mignon of Tuna and Duck Foie Gras on Charcoal Onions with a Burgundy-Butter Sauce
This luxurious dish combines seared onions, tuna, and foie gras with silky wine-butter sauce. Make the sauce first and keep it warm; once you start cooking the onions, the dish develops quickly, and the crisp seared tuna and foie gras need to be served immediately.
- Burgundy-Butter Sauce
- Dry Red Wine - 1 1/8 Cups
- Shallot - 1, cut in half
- Balsamic Vinegar - 1 cup
- Unsalted Butter - 1/8 pound (1/2 stick), cut into 4 pieces
- Salted Butter - 1/4 pound (1 stick), cut into 4 pieces
- Salt and freshly ground white pepper to taste
- Duck foie gras - One 2 oz piece
- White Onion - 1 very large, peeled and sliced 1/4 inch thick
- Carrots - 2 large, sliced very thin lengthwise into ribbons
- Zucchini - 2 large, sliced very thin lengthwise into ribbons
- Butter - 1 oz, browned
- Salt and freshly ground pepper to taste
- Tuna - Four 6-ounce steaks, trimmed into filets mignons
- Olive Oil - 2 oz
To prepare the sauce: Combine the red wine, shallot, and balsamic vinegar in a heavy saucepan and cook over medium heat until reduced to a syrup. Using a wooden spoon, Slowly incorporate the cold butter into the vinegar reduction, one piece at a time; as soon as one piece has disappeared into the developing sauce, add the next piece. Control the heat by moving the pan over or off the heat as necessary to keep the butter softening, but not so hot it develops yellow streaks of melted butter (if this occurs, remove from the heat and quickly whisk in several pieces of butter to cool the sauce). Strain through a fine-meshes sieve and adjust the seasoning to taste. Keep the sauce warm over tepid water, or in an insulated container, until ready to use.
Soak the foie gras in ice water for 5 minutes. Slice into four 1/4-inch-thick slices with a sharp, hot knife (heat the blade under hot water). Season the slices with salt and pepper. Refrigerate until ready to cook.
Heat a dry skillet over high heat until very hot. Sear the onions until blackened. Arrange the onion rings on warmed serving plates.
Bring a large pot of lightly salted water to a boil. Add the carrot and zucchini ribbons to the water and cook 2 to 3 minutes, until softened but still al dente. Drain and plunge into cold water to stop the cooking; drain again. Season with browned butter, salt, and pepper. Arrange 2 slices of each over the onions on each plate.
Season the tuna with salt and pepper. Brush with olive oil. Heat a dry skillet over high heat until very hot. Sear the tuna for 30 seconds, until lightly charred; turn and sear the same amount of time on the other side. Place a piece of tuna on the arranged vegetables on each plate. Keep warm while preparing the foie gras.
Heat a dry skillet over very high heat until smoking hot. Sear the foie gras for 10 to 15 seconds per side, until well browned with a crisp outer crust. Cap each piece of tuna with a slice of seared foie gras. Spoon three pools of sauce on each plate. Place a piece of tuna on each plate and serve.