Ingredients

• 2 small onions, halved lengthwise and thinly sliced
• 1 red bell pepper, seeded and diced
• 1/4 cup olive oil
• 1 1/3 cups diced salami, prosciutto, or smoked turkey (or a combination)
• 1 1/2 cups shredded whole-milk mozzarella
• 8 drained bottled pepperoncini (pickled Tuscan peppers, available at most supermarkets), chopped
• 1/2 teaspoon oregano, crumbled
• 1 tablespoon, plus 1 teaspoon red wine vinegar
• 4 (6-inch-long) loaves Italian bread
• 1/2 cup store-bought olive paste

Instructions

1. Preheat the oven to 450 degrees F.
2. In a heavy skillet, cook the onion and bell pepper in the oil over moderately low heat, stirring occasionally, until it is softened. While the onion and pepper are cooking, in a bowl stir together the salami, mozzarella, pepperoncini, oregano, and vinegar. Add the onion-pepper mixture.
3. Cut each piece of bread horizontally with a serrated knife without slicing all the way through, remove some of the soft inner white bread, and arrange the bread pieces cut sides up in a jelly-roll pan. Spread the bread with the olive paste. Spread the antipasto mixture on both sides of each piece of bread and bake the heros in preheated oven for 5 minutes. Season the heros with salt and pepper and re-form them, pressing the 2 sides together.