Preparation Combine cabbage and basil in large bowl. Whisk buttermilk, mayonnaise, grated onion, lemon juice, lemon peel and thyme in small bowl to blend. Add dressing to cabbage mixture; toss to coat. Season to taste with salt and pepper. (Can be prepared 3 hours ahead. Cover; refrigerate.)
Preparation Combine cabbage and basil in large bowl. Whisk buttermilk, mayonnaise, grated onion, lemon juice, lemon peel and thyme in small bowl to blend. Add dressing to cabbage mixture; toss to coat. Season to taste with salt and pepper. (Can be prepared 3 hours ahead. Cover; refrigerate.)