2 tablespoons olive oil, divided
2 medium red bell peppers, seeded and sliced into thin strips
1 cup onion sliced into half-moons
Salt and freshly ground black pepper to taste
1 pound cooked shredded chicken
1 cup diced chorizo, andouille, or other cooked spicy sausage
2 tablespoons balsamic vinegar
4 long rolls (submarine or hoagie rolls)