Start off by slicing up an onion, and frying it on medium high heat with a bit of oil until the onion browns. Stir occasionally, and it should take about five minutes.
Add in the minced garlic and fry for another minute, then remove from heat.
Spread the raw sauerkraut out in a 9x13 pan. You can use a baking sheet, metal pan, or foil pan for this, wherever you feel comfortable putting into the smoker. Spread the sauerkraut out so that it forms a thin even layer, and then spread the onion and garlic mixture on top. The goal is to create as much surface area for the kraut to pick up smoke as possible.
Smoke the tray at 250F for 1 to 2 hours. Check the kraut after 1 hour and evaluate how strong the flavor is. If you want a stronger flavor, go for the second hour.