In a small bowl, mix together dressing ingredients — olive oil, vinegar, Italian seasoning, and garlic.
In a large bowl, toss together tomatoes, red onion, mozzarella pearls, garbanzo beans, pasta, and pepperoni. Add dressing, stirring to coat.
Pasta mixture can marinate overnight or be served immediately. Dress plates with spinach and top with pasta mixture.
Red or white wine vinegar can be used in place of balsamic vinegar.
Per serving: 671 calories, 32 grams fat (9 grams saturated fat), 61 milligrams cholesterol, 605 milligrams sodium, 66 grams total carbohydrates, 14 grams fiber, 34 grams protein.