Chopped Sandwich

Name: Chopped Sandwich
Ingredients: 1 Roma tomato, sliced; 1/2 small red onion, thinly sliced (about 1/2 c.); 4 oz. Black Forest or capicola ham, sliced; 4 oz. provolone, sliced; 2 oz. genoa salami; 2 oz. hot soppressata or pepperoni; 1 c. shredded romaine; 1/3 c. sliced roasted red peppers; 1/4 c. sliced drained peperoncini; 1/3 c. mayonnaise; 3 tbsp. store-bought or homemade pesto; 2 tbsp. red wine vinegar; 1/2 tsp. onion powder; 1/2 tsp. Italian seasoning; Kosher salt; Freshly ground black pepper; 2 (10) ciabatta rolls, halved, toasted