Cook tortellini in boiling salted water until al dente, 7-8 minutes. Pour into colander and run under cold water to stop cooking. Drain well and toss gently with 2 tablespoons olive oil, 1/2 teaspoon each salt and freshly ground black pepper. Set aside.
Put all ingredients except for olive oil into small bowl. Whisk until blended. Slowly add olive oil and whisk until emulsified. Taste and adjust seasonings if needed. (May be prepared ahead and refrigerated. Bring to room temperature before using.)
At serving time, combine cooled tortellini, Kalamata olives, feta cheese, spinach, pine nuts and sun-dried tomatoes in a large bowl. Pour in dressing and toss gently to combine. Transfer to a large serving bowl (lined with whole spinach leaves if desired). The salad may be garnished with additional crumbled feta cheese, pine nuts and/or Kalamata olives.