Put the spinach in a small bowl and place in the steamer for 2-3 minutes until it wilts. Remove the spinach, squeeze to remove as much moisture as possible, then cut into shreds and place in a dry bowl. Add the cream cheese, dill and some salt and pepper, and mix well.
Cut a slice along the side of the chicken breast but not all the way through, to create a pocket. Stuff the spinach mixture into the pocket, then seal the breast closed using cocktail sticks.
Put the stuffed breast on a small plate and place in the steamer to cook for 20 minutes.
Remove the cocktail sticks and allow to cool slightly before slicing.