Supreme Pizza Pasta Salad

• 2 plum tomatoes, seeded and chopped
• 1/2 medium red onion, chopped
• 8 fresh white button mushrooms, sliced
• 1 small green bell pepper, seeded and chopped
• 1 stick pepperoni, casing removed and cut into a small dice
• 1 pound ball fresh mozzarella or fresh smoked mozzarella, diced
• 20 leaves fresh basil, torn or thinly sliced
• 1 pound wagon wheel pasta, cooked to al dente and cooled under cold water, then drained

Dressing:

• 1 teaspoon garlic salt
• 1 teaspoon dried oregano leaves or Italian dried seasoning
• 1 rounded tablespoon tomato paste
• 2 tablespoons red wine vinegar, eyeball it
• 1/3 cup extra-virgin olive oil, eyeball it
• Freshly ground black pepper