Place rabbit pieces in a non aluminum shallow dish. In a small bowl, whisk together cider, mustard, green peppercorns, thyme, black peppercorns and red-pepper flakes and pour over the rabbit, turning to coat well. Cover and marinate in the refrigerator for 24 hours, turning occasionally. Preheat oven to 450 deg F. Brush marinade off the rabbit pieces, reserving it. Heat oil in a non-stick skillet over medium-heat, and sear the rabbit pieces for 1 to 2 minutes per side, or until lightly browned. Place them on a lightly oiled rack in a roasting pan. Roast for 35 to 40 minutes, basting occasionally with the reserved marinade, until the juices run clear when the rabbit is pierced with a skewer. Meanwhile, core and slice apple into 1/2-inch slices. Toss with lemon juice. Heat one teaspoon oil in a nonstick skillet over medium heat. Add apples and maple syrup and cook for 3 to 4 minutes, or until golden, turning once. Arrange rabbit on a serving platter and garnish with apple slices and fresh thyme, if using. Serves 4.