Remove the rack from an old roasting pan or baking sheet and line the bottom with aluminum foil. (Use old equipment because this recipe may cause blackening. The rack should be flat.) Place the foil-lined pan on the grill. Preheat the grill, setting the burners to high.
On a clean surface, use a chef’s knife to remove the back from the chicken and lay the bird flat. Brush the breasts and legs with soy sauce. Refrigerate.
Using a mortar and pestle or a coffee grinder, coarsely crush the coffee beans and spices.
Spread the coffee–spice mixture in the roasting pan so that it covers an area roughly the size of the chicken. Heat until the mixture starts to smoke, 2 to 3 minutes.
Generously oil the rack of the roasting pan. Place the chicken on the rack, breast side down. Place the rack on the roasting pan. Seal tightly with aluminum foil. (Wear oven mitts to guard against burns.) Close the grill’s cover. Lower the burners to medium. Cook until an instant-read meat thermometer inserted in a leg, without touching the bone, reads 82°C (180°F). Serve with American Salad (page 45) and All-Dressed Stuffed Potatoes.