Rinse the rabbits and pat them dry with paper towels. Cut each one into three pieces; the hind legs, the front legs, and the loin. Cut the hind and front leg sections into 2 pieces each, leaving the loin in one piece. You should now have 5 sections per rabbit.

Place the rabbit pieces in a large deep nonreactive bowl.

In a small sauce pan over medium heat, reduce the orange juice to half a cup. In a small bowl, combine the pepper, fennel, saffron, cayenne, and salt. Add the reduced orange juice and the lemon juice, whisk together, and let stand for 10 or 15 minutes. Add the honey and mix together. Pour this mixture over the rabbit pieces, toss so that each one is evenly coated, and let sit at room temperature for about 1 hour, loosely covered. Toss the pieces every 15 minutes.

Preheat the oven to 400 degrees. Remove the rabbit from the marinade and place on a rack in a roasting pan. Roast the rabbit for 20 to 25 minutes, until done through with no trace of pink remaining. Baste once with the marinade halfway through the cooking time, then again when you remove the rabbit from the oven.

Place the rabbit pieces on a platter and surround them with sprigs of watercress and wedges of lemon. Drain the onion slices briefly on paper towels, separate them into rings and scatter them over the top.