Preheat the oven to 400 degrees F. Season the potatoes with olive oil, salt and pepper. Place in the oven and roast until tender, about 1 hour. Remove from the oven and peel away the skin from each potato. Place the potatoes in a saucepan over medium heat. Add the butter. Season with salt and pepper. Using a hand-held masher, mash the potatoes until they are slightly smooth. Add the cream and incorporate thoroughly. Add the bourbon to taste. Reason with salt and pepper. Set aside, keeping warm. Prepare the smoker using the cinnamon sticks instead of the wood chips. Season the loin with the olive oil, salt and pepper. Place in the smoker, cover and smoke for 15 to 20 minutes. Remove from the smoker. In a large saute pan, over medium heat, add 2 tablespoons of the vegetable oil. When the pan is hot, sear the loin for 2 to 3 minutes on each side. In saute pan, over medium heat, combine the remaining 2 tablespoons of olive oil and flour. Mix well. Cook for about 10 minutes for a dark roux or until the color of chocolate, stirring constantly. Add the onions. Season with salt and pepper. Cook until the onions are wilted, about 6 minutes. Stir in the veal stock and bring to a boil. Reduce the heat to medium low and simmer for 30 minutes. Reseason if necessary. Remove from the heat and keep warm.
Place loin in the oven and roast for about 20 minutes for medium rare. Remove from the oven and rest for 5 minutes before slicing. Place a spoonful of the sweet potatoes in the center of each plate. Mound the greens around the sweet potatoes. Lay the slices of venison around the potatoes. Spoon some of the gravy over the meat. Garnish with green onions.