In a large skillet over medium heat, heat the oil.
Add the onions and peppers and season with salt and pepper. Cook, stirring occasionally, until very soft, about
8 to 10 minutes.
Stir in the chicken and Italian seasoning until combined. Cook, stirring occasionally, until chicken is golden and no longer pink inside, about 10 minutes.
Place sub buns on a baking sheet lined with parchment paper.
Slice each in half lengthwise and spread open.
Cut provolone slices in half and add two half pieces to each deli roll.