Fill a large pot with water, add about a tablespoon of salt, and bring to a rolling boil over high heat.
Stir in the shells pasta and return to a boil.
Cook the until the pasta is al dente, usually 8 to 10 minutes. Follow the box directions for the time.
Rinse with cold water to cool. Drain and set aside.
In a separate small bowl add the oil, lemon juice, vinegar, mustard, garlic, oregano, salt and pepper.
Whisk until well blended.
Combine the spinach, drained pasta, pine nuts, sun dried tomatoes, scallions and parmesan cheese. Toss.
Add the dressing, toss and refrigerate.