1.5 pounds boneless skinless chicken breast – thinly sliced
1.25 teaspoons kosher salt
0.5 teaspoons black pepper
2 tablespoons neutral oil
8 slices provolone cheese
2 tablespoons water
pickled hot cherry peppers – sliced (for serving)
Instructions
Split the hoagie rolls lengthwise without cutting all the way through; set aside.
Thinly slice the onion and the chicken breast into bite-size strips.
Heat 1 tablespoon of the oil on a large griddle or skillet over medium-high heat until shimmering. Add the onion and a pinch of the salt; cook, stirring occasionally, until tender and golden at the edges, 8–10 minutes. Push to one side of the pan.
Add the remaining 1 tablespoon oil to the open side of the pan. Add the chicken in an even layer; season with the remaining salt and the black pepper. Cook without moving until the underside turns opaque and lightly browned, about 2 minutes, then chop or break up the chicken with a spatula and cook, stirring, until just cooked through, 3–4 minutes.
Fold the onions into the chicken and toss to combine. Divide the mixture into 4 equal mounds, roughly roll-length.
Top each mound with 2 slices provolone. Splash the water around the mounds and cover the pan with a lid or foil to steam-melt the cheese until fully melted, 30–60 seconds.
While the cheese melts, warm the split rolls cut-side down on the griddle until lightly toasted, 1–2 minutes.
Using a wide spatula, lift each cheesy mound into a roll, nestling the filling into the bread. Press gently to set.
Serve hot with pickled hot cherry peppers on the side for serving.