In a 12-inch cast-iron skillet over medium-low heat, cook bacon cubes until crisp, about 10 to 12 minutes, stirring occasionally. With a slotted spoon, remove bacon to a paper-towel-lined plate. Increase heat to medium-high and add four cabbage wedges to the bacon fat. Cook until charred, 5 minutes on each side. Remove the wedges to a plate and repeat with the remaining four wedges. (If the pan is dry, add a drizzle of canola oil before the second batch.) Turn off heat.