Peel the grapes, being careful to leave them attached to the stem.
Melt the duck fat in a sauté pan; sauté the apple and pear wedges; add the grape bunches, and finally the quartered figs. Let cook, stirring often and gently. The fruit juices will caramelize. Sprinkle with sugar at the last minute.
Over low heat, reduce the port by three quarters to obtain a syrupy reduction.
Season the escalopes of foie gras with salt and pepper. Grill for 4 to 5 minutes on each side over a wood fire (containing some vine branches if possible.) Once the foie gras is cooked, place the escalopes onto paper towels.
Presentation: Attractively arrange the roasted fruits at the top of each plate, followed by an escalope of foie gras. Add a little Guérande salt and cracked pepper to the foie gras. Spoon the hot port sauce over top. Serve immediately.