Toast walnuts in a pan on low heat for a few minutes until fragrant. Remove from pan and let cool while you complete salad.
Wash and dry spinach leaves. Add to large serving bowl.
Gently wash raspberries in colander and let dry.
Slice nectarine in half. Remove stone. Lightly drizzle olive oil onto cut side of fruit. Grill for approximately 5 minutes on cast iron grill pan. Let pan get hot before adding fruit. For grill cross marks, after a few minutes, turn the fruit so you have lines going both ways from the grill pan. Slice or dice fruit for salad with your preferred size.
Pour some of the dressing over the spinach leaves until lightly coated. Add walnuts, nectarine and any remaining shallots and gently toss salad. Add raspberries last as they are fragile. Serve and enjoy!