Rinse the kale and then remove any large center ribs. Stack the leaves and, with a sharp knife, cut them into fine shreds. Peel the carrot and shred it. Remove the outer leaves from the radicchio and then finely shred that as well. Put all in a bowl.
Make the dressing by mixing all the ingredients together in a mason jar or small bowl Shake or whisk well to combine. Taste to adjust any of the ingredients.
Pour the dressing over the salad. Use enough to moisten everything, but not soak it Let the salad sit for an hour or two in the fridge if you like, before serving. Toss with the sunflower seeds just before eating, and top with the cheese, if using.