Step 1: Build the base by adding chopped romaine and arugula into a large mixing bowl and tossing lightly to combine.
Step 2: Add fresh vegetables including cherry tomatoes, cucumber, red onion, olives, and pepperoncini, spreading them out evenly.
Step 3: Layer in meats and cheese by adding salami, pepperoni, mozzarella, and parmesan across the top.
Step 4: Mix the dressing by whisking together olive oil, red wine vinegar, Dijon mustard, garlic powder, and salt in a small bowl until thickened.
Step 5: Toss and finish by pouring dressing over the salad, tossing gently until coated, and sprinkling with dried oregano and black pepper.