Using a 12 inch cast iron skillet, heat 1 tablespoon of olive oil over medium heat. Once hot, add in the Italian sausage and cook until no pink remains. Remove from skillet and place in a bowl on the side.
Add in the kale, and cook for an additional 5 minutes until the kale has wilted. Add the sausage back in the skillet and mix everything together until evenly distributed around the bottom of the skillet.