Shred the Vegetables: Finely shred the half cabbage with a sharp knife. Cut the carrot into thin julienne matchsticks or grate it using a box grater. Combine them both in a large bowl.
Add the Dressing: Measure the light mayonnaise, vinegar, sugar, and a pinch of salt, adding them directly over the shredded vegetables.
Massage the Slaw: Using clean hands, gently massage the cabbage and carrots with the dressing for 1 to 2 minutes. You will feel the cabbage start to soften slightly in your hands.
Rest and Serve: Let the coleslaw rest in the fridge or on the counter for at least 5 minutes before serving to let the flavors develop. Give it one quick stir before plating.