How to Make It
Using poultry shears, remove the duck backbone and the wings at the second joint. Cut the duck into 2 breasts and 2 whole legs and trim off the excess fat.
In a small skillet, toast the white and black peppercorns, the cloves and the crushed red pepper over moderate heat until fragrant, 2 minutes. Transfer to a food processor. Add the salt, rosemary, thyme, garlic and orange zest and process until finely ground, 2 minutes.
Transfer the salt mixture to a large bowl, add the duck and dredge well. Set the duck breasts and legs in a baking pan, skin side up. Sprinkle lightly with more of the salt, cover with plastic wrap and refrigerate for 6 to 8 hours.
Preheat the oven to 275°. Rinse the duck pieces and arrange them in a deep baking dish just large enough to hold them. Pour the duck fat over the duck so it's completely submerged. Cook the duck for 2 hours and 15 minutes, turning occasionally, until fork-tender; the skin will separate from the meat when the duck is done. Let the duck cool in the fat, then refrigerate for 8 hours.