1. To toast walnuts: Preheat oven to 350°F. On small baking sheet, place walnuts in oven until they are fragrant and look a shade darker, about 5 minutes. Remove from oven, and set aside to cool.
2. To make slaw: Strip ruffly leaves from kale's stems. Stack and bunch the leaves together on cutting board and use knife to cut across stack to make skinny slivers of kale. Place garlic, lemon juice, oil, and salt in large bowl, add kale and toss roughly with tongs to soften it. Taste, adding more lemon, oil, or salt to taste.
3. Add Parmesan cheese and walnuts and serve.