Place the duck breasts on a sheet pan, skin side up. Sprinkle with salt and roast for about 20 minutes, until medium-rare. Remove from the oven, cover tightly with aluminum foil, and allow to sit for 10 to 15 minutes. Remove and discard the fat and skin on top (unless you\'re making cracklings), slice the duck, and then cut the slices crosswise into julienned pieces.
Meanwhile, in a small bowl, combine the shallots, sherry vinegar, orange zest, and 1 1/2 teaspoons of salt. Whisk in the olive oil and set aside.
For the salad, trim the bottom half-inch from the endive and cut them diagonally into 1/2-inch slices. Separate the leaves and discard the cores. Place the slices in a large salad bowl. Add the mache leaves, oranges, raspberries, and toasted pecans. Toss with enough dressing to moisten. Gently toss in the warm duck meat and serve immediately.