1. Heat pine nuts in a small skillet over medium-high heat, stirring constantly, 5 minutes or until toasted and fragrant.
2. Coarsely chop spinach. Toss together spinach, grapes, feta cheese, and vinaigrette in a serving bowl. Sprinkle with pine nuts, and serve immediately.
Note: For testing purposes only, we used Newman's Own Light Raspberry & Walnut Dressing.