Put the salt in a small bowl. Finely grind the peppercorns, allspice, juniper, cloves, and bay leaves in a mortar or spice mill. Mix the ground spices with the salt. Add the garlic.
Trim the duck breasts and lay them on a baking sheet or platter. Season each breast on both sides with the spice mixture, massaging the seasoning into the flesh with your fingers.
Now pair up the breasts, and make each pair into a sort of sandwich—that is, stack one breast on top of the other, skin sides out. With butcher’s twine, tie the “sandwiches” together, to make 3 compact little roasts. Wrap and refrigerate for at least several hours, or overnight.
Place the breasts in a shallow roasting pan and let them come to room temperature.
Remove the duck from the oven and pour off any accumulated fat. Let the
Remove the twine and cut the duck breasts crosswise into ⅛-inch-thick slices. Arrange the slices on a warmed platter, and garnish with the baked figs and liver toasts. Drizzle a little aged balsamic vinegar over the duck and the figs.