Set a large cast iron skillet over medium heat. When the skillet is hot, add the ground beef and use a spatula to break it up as it browns. You don’t need to add any oil. Once it is cooked through and no longer pink, scoot all the meat to one side. Hold onto the handle to tilt the skillet and use a large spoon to scoop out and discard as much fat as you’d like. Then, add the taco seasoning and water and cook for about 2 minutes, stirring frequently. Turn the burner off and set the skillet aside.