Heat 1 tablespoon of the oil in a large skillet over medium-high heat. Add the bell peppers and onion and cook, stirring, until softened, about 5 minutes. Season with salt and pepper. Remove the vegetables from the skillet and set aside.
Heat the remaining 1 tablespoon oil in the same skillet over medium-high heat. Add the chicken and cook until golden brown, 3 to 5 minutes. Add the sausage and vinegar and cook for 1 minute to heat through.
Using tongs, arrange the chicken mixture on the open rolls, top with the fried peppers and serve.