In large bowl, separate radicchio leaves and tear into bite-sized pieces. Add shaved cabbage, apple slices, onion, and grapes. Set aside.
In separate bowl, combine dressing ingredients. Whisk vigorously until emulsified. Drizzle over salad and gently toss until coated. Scatter toasted almonds and blue cheese overtop and serve.
To make ahead, refrigerate salad and dressing separately.
Recipe Notes
Per serving: 147 calories; 3 g protein; 12 g fat (2 g sat. fat); 9 g total carbohydrates (5 g sugar, 2 g fiber); 143 mg sodium