In a large heavy bottomed skillet cook bacon over moderate heat, stirring until crisp. Transfer bacon with a slotted spoon to paper towels to drain. Pour off and discard all but 3 tablespoons of the fat.
Add mushrooms to the pan and sauté until golden. Add kale and cook turning with tongs until wilted and bright green, about 1 minute.
Add ½c water and simmer, partially covered, until just tender, about 5 minutes.
Add the bacon, toss and season with salt and pepper.