Place the walnuts in a skillet set over medium heat. Cook and stir until lightly toasted and aromatic, about 4 to 5 minutes. Remove from the heat and set aside.
Combine the next 5 ingredients in a medium bowl. Add the salads greens and toss to coat. Divide and mound the greens on 4 plates. Divide and top greens with the apple, cheese and nuts, and then serve.