Preheat your griddle to 375° or a large twelve-inch skillet over medium/medium-high heat and preheat your oven to 350 degrees.
Once hot; add in a table spoon of olive oil and add in the peppers and onions. Stir to coat in oil and then leave them be for a minute or two to create a good caramelization and color. Continue to cook the onions and peppers until they are soft yet still a bit firm, transfer them to a clean bowl.
Add the remaining oil to the griddle or pan, and add in the chicken. Work in batches so the chicken has a chance to color and cook evenly. Once cooked, transfer the chicken to the bowl with the peppers and onions and toss.
Divide the chicken/pepper mixture among the split sub buns and top with chopped jalapenos {if desired} and two slices of smoked Provolone per sandwich.
Slide the sandwiches into your preheated oven for 5-8 minutes or until the cheese is melted.
Smear mayonnaise (if desired) on the underneath of the top bun and serve warm!