Remove the meat from the pheasant. Chop into small pieces and marinate in the red vermouth overnight. Preheat the oven to 350 degrees F. Line a terrine mold with bacon. Drain the pheasant meat and arrange half in the mold. Season with salt and pepper. Put a layer of walnuts on top and fill the rest of the mold with the pheasant. Season. Cover with bacon. Set the mold in a bain marie and cook in the preheated oven 45 minutes. When cooked, ease the terrine away from sides of the mold and leave to cool in the mold. Turn out for serving.