Cut the kale into thin slivers and place it into a bowl.
Add the dressing and ½ cup of the feta to a small blender or cup for using an immersion blender.
Blend the feta and the dressing until smooth.
Add 2 tablespoons of the feta dressing to the kale and massage it with your hands for 2 to 3 minutes, until the leaves turn darker, glossy, and shrink by about a third.
Cut the apple into matchsticks.
In a small bowl, toss the apple matchsticks with 2 tablespoons of the feta dressing to keep them from turning brown.
Add the apples, remaining feta, and salad topper to the kale.