Slice the chicken thinly using a very sharp knife.
Put the sliced chicken in a bowl and season it with salt, pepper, and Worcestershire sauce.
Heat 1 1/2 tablespoons of extra virgin olive oil over medium heat in a pan.
Add the peppers and onions, toss to coat in oil, cover, and simmer for 10 to 15 minutes, stirring occasionally, until softened.
If required, add a few tablespoons of water to prevent sticking.
Set aside the peppers in a mixing bowl.
Heat the remaining 1 1/2 tablespoons olive oil over medium-high heat and add the chicken, tossing often until cooked through and lightly browned.
Turn the heat down to medium and drain the fat.
Return the peppers to the pan and toss to reheat.
Spread the mustard blend on top of the split hoagie rolls.
Top with cheese and serve immediately.
Put the sandwiches under the broiler to warm and melt the cheese if necessary.