The endives are grilled first over a relatively low fire, so if you're grilling over charcoal, keep a chimney starter filled with hot coals for raising the temperature to moderately hot for the duck. Slideshow: More Incredible Duck Recipes
In a small saucepan, combine the 1/2 cup olive oil with the rosemary and juniper berries. Simmer over low heat for 2 minutes. Remove from the heat, cover and let stand for at least 20 minutes.
Light a grill. Brush the endives with olive oil and season with salt and pepper. Grill over a low fire, turning, for about 20 minutes, or until the endives are almost tender. Transfer the endives to a platter and cover loosely with foil.
Season the duck breasts with salt and pepper and grill, skin side down, over a moderately hot fire for 4 minutes. Turn the duck breasts and grill for 3 minutes longer for medium rare. Transfer the duck to a carving board to rest for about 5 minutes. Slice the duck breasts crosswise 1/2 inch thick and arrange the slices on a large warmed platter. Return the endives to the grill briefly to reheat, then add to the platter. Drizzle the duck with the rosemary-juniper oil and serve.
Turn to an assertive, mouth-filling Italian red that can harmonize with the rich, smoky duck.