1. Set up your smoker following the manufacturer’s instructions and preheat to 400°F. Add enough wood for 1 hour of smoking as specified by the manufacturer.
2. Scrub the potatoes on all sides with a vegetable brush. Rinse well under cold running water and blot dry with paper towels. Prick each potato several times with a fork (this keeps the spud from exploding and facilitates the smoke absorption). Brush or rub the potato on all sides with the bacon fat and season generously with salt and pepper.
3. Place the potatoes on the smoker rack. Smoke until the skins are crisp and the potatoes are tender in the center (they’ll be easy to pierce with a slender metal skewer), about 1 hour.
4. Meanwhile, place the bacon in a cold skillet and fry over medium heat until browned and crisp, 3 to 4 minutes. Drain off the bacon fat (save the fat for future potatoes).
5. Transfer the potatoes to a cutting board and let cool slightly. Cut each potato in half lengthwise. Using a spoon, scrape out most of the potato flesh, leaving a 1/4-inch-thick shell. (It’s easier to scoop the potatoes when warm.) Cut the potato flesh into 1/2-inch dice and place in a bowl.
6. Add the bacon, 4 tablespoons of the butter, the scallions, and cheese to the potato flesh and gently stir to mix. Stir in the sour cream and salt and pepper to taste; the mixture should be highly seasoned. Stir as little and as gently as possible so as to leave some texture to the potatoes.
7. Spoon the potato mixture back into the potato shells, mounding it in the center. Top each potato half with a thin slice of the remaining butter and sprinkle with paprika. The potatoes can be prepared up to 24 hours ahead to this stage, covered, and refrigerated.
8. Just before serving, preheat your smoker to 400°F. Add enough wood for 30 minutes of smoking. Place the potatoes in a shallow aluminum foil pan and re-smoke them until browned and bubbling, 15 to 20 minutes. (Or you can heat them in a 400°F oven.)
Note: Some smokers won’t get hotter than 275°F. In this case, increase the smoking time to 2 to 3 hours and the re-smoking time to 40 to 60 minutes.
Reprinted with permission from Project Smoke by Steven Raichlen, copyright © 2016. Published by Workman Publishing.
"Vegetables are perishable, so we don't have any indication of what they looked like 500 years ago," says James Nienhuis, a professor in the Department of Horticulture at the University of Wisconsin.