In a small mixing bowl, combine the peppercorns, thyme, bay leaves, cloves, garlic, and 1 teaspoon whole juniper berries.
In a saucepan combine the water, brown sugar and salt. Bring to a boil and stir to dissolve the sugar and salt. Remove from the heat, add spice mixture, and steep for 1 hour. Place the duck breast in a glass or plastic container. Pour the seasoned brine over the duck to cover completely. Cover with plastic wrap and refrigerate for 48 hours, turning the breasts several times.
Remove the duck breasts from the brine and rinse thoroughly under running water. Pat dry with a towel.
Preheat the oven to 250 degrees F.
In a small bowl, combine the crushed juniper berries and ground black pepper. Using the palm and heel of your hands, press 2/3 of the berry and pepper mixture into the underside of the breasts. Press the remaining mixture onto the skin side. Place the breasts, skin side down, on a rack in a roasting pan and cook for 1 to 1 1/2 hours.
Remove and let cool for 30 minutes. Wrap the breasts tightly in plastic wrap and place in an airtight container. Store in the refrigerator for at least 1 week before using.
To serve, remove the meat from the plastic wrap and slice thinly. Serve with sliced French bread and other accompaniments as appetizers or hors d'oeuvres.
Yield: 4 to 6 servings