- 3 1⁄2 tablespoons sugar
- 1⁄2 cup plus 3 tablespoons red wine vinegar
- 3 quinces, Granny Smith apples or firm Bartlett pears, peeled, cored and diced (reserve peelings)
- 1⁄2 cup vegetable or chicken stock, Salt to taste
- 1⁄2 cup duck demi-glace or enriched stock
- 1 (2-pound) whole boneless Moulard duck breast, excess fat removed, skin and fat scored in crosshatch, patted dry
- Salt and pepper to taste
To prepare the sauce: Heat 2 tablespoons sugar in a heavy saucepan set over medium heat until lightly caramelized. (Handle carefully, hot sugar can cause serious burns.) Stir in 1/2 cup vinegar and cook over high heat about 2 minutes, until reduced in volume by half. Add diced quince, stock and salt, and partially cover (placing pot lid so that steam can escape). Reduce heat to low; cook for 25 to 30 minutes, stirring occasionally, until fruit is tender. Purée in a blender or with a hand mixer until smooth. Return to pan and keep warm.
Heat remaining 1 1 /2 tablespoons sugar in a small saucepan set over medium heat until lightly caramelized. Add the remaining 3 tablespoons vinegar and heat until reduced in volume by half. Add quince peelings and demi-glace. Cook sauce over low heat for 30 minutes, strain and keep warm.
To cook the duck: Season the magret with salt and pepper. Heat a heavy skillet over medium-high heat. Place duck breast in pan, skin side down, without adding any fat. Cook for 8 minutes; checking to avoid burning. Remove fat as it accumulates. Flip breast over, reduce heat to medium and cook 4 minutes longer. Remove duck from heat and keep warm.
To serve: Place a small amount of quince purée into the center of each of 4 warmed plates. Cut the duck breast in half, then cut it against the grain into 1/4-inch slices. Apportion slices evenly between the 4 plates, fanning them over the purée. Spoon a small amount of the sauce over them.